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Cough
Depiction of cough
Pronunciation
SpecialtyPulmonology, otorhinolaryngology
Coughing
The sound of a person coughing.
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A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.[1] Coughing into one's elbow or toward the ground—rather than forward at breathing height—can reduce the spread of infectious droplets in the air.[2]

Frequent coughing usually indicates the presence of a disease. Many viruses and bacteria benefit, from an evolutionary perspective, by causing the host to cough, which helps to spread the disease to new hosts. Irregular coughing is usually caused by a respiratory tract infection but can also be triggered by choking, smoking, air pollution,[1] asthma, gastroesophageal reflux disease, post-nasal drip, chronic bronchitis, lung tumors, heart failure and medications such as angiotensin-converting-enzyme inhibitors (ACE inhibitors) and beta blockers.[3]

Treatment should target the cause; for example, smoking cessation or discontinuing ACE inhibitors. Cough suppressants such as codeine or dextromethorphan are frequently prescribed, but are not recommended for children. Other treatment options may target airway inflammation or may promote mucus expectoration. As it is a natural protective reflex, suppressing the cough reflex might have damaging effects, especially if the cough is productive (producing phlegm).[4]

Presentation

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Shadowgraph videos of the outer airflow during a cough, comparing unmasked coughing with several methods of covering one's mouth and nose: coughing into a fist, a cupped hand, a tissue, a "coughcatcher" device, a surgical mask, and an N95 mask

Complications

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The complications of coughing can be classified as either acute or chronic. Acute complications include cough syncope (fainting spells due to decreased blood flow to the brain when coughs are prolonged and forceful), insomnia, cough-induced vomiting, subconjunctival hemorrhage or "red eye", coughing defecation and in women with a prolapsed uterus, cough urination. Chronic complications are common and include abdominal or pelvic hernias, fatigue fractures of lower ribs and costochondritis. Chronic or violent coughing can contribute to damage to the pelvic floor and a possible cystocele.[5]

Differential diagnosis

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A cough in children may be either a normal physiological reflex or due to an underlying cause.[6] In healthy children it may be normal in the absence of any disease to cough ten times a day.[6] The most common cause of an acute or subacute cough is a viral respiratory tract infection.[6] A healthy adult also coughs 18.6 times a day on average, but in the population with respiratory disease the geometric mean frequency is 275 times a day.[7] In adults with a chronic cough, i.e. a cough longer than 8 weeks, more than 90% of cases are due to post-nasal drip, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease.[6] The causes of chronic cough are similar in children with the addition of bacterial bronchitis.[6]

Infections

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A cough can be the result of a respiratory tract infection such as the common cold, COVID-19, acute bronchitis, pneumonia, pertussis, or tuberculosis. In the vast majority of cases, acute coughs, i.e. coughs shorter than 3 weeks, are due to the common cold.[8] In people with a normal chest X-ray, tuberculosis is a rare finding. Pertussis is increasingly being recognised as a cause of troublesome coughing in adults.

After a respiratory tract infection has cleared, the person may be left with a postinfectious cough. This typically is a dry, non-productive cough that produces no phlegm. Symptoms may include a tightness in the chest, and a tickle in the throat. This cough may often persist for weeks after an illness. The cause of the cough may be inflammation similar to that observed in repetitive stress disorders such as carpal tunnel syndrome. The repetition of coughing produces inflammation which produces discomfort, which in turn produces more coughing.[9] Postinfectious cough typically does not respond to conventional cough treatments. Medication used for postinfectious coughs may include ipratropium[9] to treat the inflammation, as well as cough suppressants to reduce frequency of the cough until inflammation clears.[10] Inflammation may increase sensitivity to other existing issues such as allergies, and treatment of other causes of coughs (such as use of an air purifier or allergy medicines) may help speed recovery.[11]

Reactive airway disease

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When coughing is the only complaint of a person who meets the criteria for asthma (bronchial hyperresponsiveness and reversibility), this is termed cough-variant asthma. Atopic cough and eosinophilic bronchitis are related conditions. Atopic cough occurs in individuals with a family history of atopy (an allergic condition), abundant eosinophils in the sputum, but with normal airway function and responsiveness. Eosinophilic bronchitis is characterized by eosinophils in sputum and in bronchoalveolar lavage fluid without airway hyperresponsiveness or an atopic background.[12] This condition responds to treatment with corticosteroids. Cough can also worsen in an acute exacerbation of chronic obstructive pulmonary disease.

Asthma is a common cause of chronic cough in adults and children. Coughing may be the only symptom the person has from their asthma, or asthma symptoms may also include wheezing, shortness of breath, and a tight feeling in their chest. Depending on how severe the asthma is, it can be treated with bronchodilators (medicine which causes the airways to open up) or inhaled steroids. Treatment of the asthma should make the cough go away.

Chronic bronchitis is defined clinically as a persistent cough that produces sputum (phlegm) and mucus, for at least three months in two consecutive years. Chronic bronchitis is often the cause of "smoker's cough". The tobacco smoke causes inflammation, secretion of mucus into the airway, and difficulty clearing that mucus out of the airways. Coughing helps clear those secretions out. May be treated by quitting smoking. May also be caused by pneumoconiosis and long-term fume inhalation.

Gastroesophageal reflux

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In people with unexplained cough, gastroesophageal reflux disease should be considered.[6] This occurs when acidic contents of the stomach come back up into the esophagus. Symptoms usually associated with GERD include heartburn, sour taste in the mouth, or a feeling of acid reflux in the chest, although, more than half of the people with cough from GERD do not have any other symptoms. An esophageal pH monitor can confirm the diagnosis of GERD. Sometimes GERD can complicate respiratory ailments related to cough, such as asthma or bronchitis. The treatment involves anti-acid medications and lifestyle changes with surgery indicated in cases not manageable with conservative measures.

Air pollution

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Coughing may be caused by air pollution including tobacco smoke, particulate matter, irritant gases, and dampness in a home.[6] The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics. People who exercise outdoors on hot, smoggy days, for example, increase their exposure to pollutants in the air.

Foreign body

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A foreign body can sometimes be suspected, for example if the cough started suddenly when the patient was eating. Rarely, sutures left behind inside the airway branches can cause coughing. A cough can be triggered by dryness from mouth breathing or recurrent aspiration of food into the windpipe in people with swallowing difficulties.[13][14]

Drug-induced cough

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Drugs used for treatments other than coughs, such as ACE inhibitors which are often used to treat high blood pressure, can sometimes cause cough as a side effect, and stopping their use will stop the cough.[15] Beta blockers similarly cause cough as an adverse event.[3]

Habit cough

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A habit cough is one that responds to behavioral or psychiatric therapy after organic causes have been excluded. Absence of the cough during sleep is common, but not diagnostic. A tic cough is thought to be more common in children than in adults.[16]

Neurogenic cough

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Some cases of chronic cough may be attributed to a sensory neuropathic disorder.[17] Treatment for neurogenic cough may include the use of certain neuralgia medications. Coughing may occur in tic disorders such as Tourette syndrome, although it should be distinguished from throat-clearing in this disorder.

Other

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Cough may also be caused by conditions affecting the lung tissue such as bronchiectasis, cystic fibrosis, interstitial lung diseases and sarcoidosis. Coughing can also be triggered by benign or malignant lung tumors or mediastinal masses. Through irritation of the nerve, diseases of the external auditory canal (wax, for example) can also cause cough. Cardiovascular diseases associated with cough are heart failure, pulmonary infarction and aortic aneurysm. Nocturnal cough is associated with heart failure, as the left ventricle doesn't effectively pump blood forward, resulting in blood being backed up in the pulmonary veins, which in turn causing pulmonary edema and resultant cough.[18] Other causes of nocturnal cough include asthma, post-nasal drip and gastroesophageal reflux disease (GERD).[19] Another cause of cough occurring preferentially in supine position is recurrent aspiration.[18] Cough can also be a symptom of mast cell activation syndrome (MCAS).[20]

Given its irritant nature to mammal tissues, capsaicin is widely used to determine the cough threshold and as a tussive stimulant in clinical research of cough suppressants. Capsaicin is what makes chili peppers spicy, and might explain why workers in factories with these fruits can develop a cough.

Coughing may also be used for social reasons, and as such is not always involuntary. A voluntary cough, often written as "ahem", can be used to attract attention or express displeasure, as a form of nonverbal, paralingual metacommunication.[21][22]

Airway clearance

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Further information: Airway clearance therapy

Coughing, and huffing are important ways of removing mucus as sputum in many conditions such as cystic fibrosis, and chronic bronchitis.

Pathophysiology

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Coughing is viewed as a public health issue.

A cough is a protective reflex in healthy individuals which is influenced by psychological factors.[6] The cough reflex is initiated by stimulation of two different classes of afferent nerves, namely the myelinated rapidly adapting receptors, and nonmyelinated C-fibers with endings in the lung.[23]

Diagnostic approach

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The type of cough may help in the diagnosis. For instance, an inspiratory "whooping" sound on coughing almost doubles the likelihood that the illness is pertussis.

Blood may occur in small amounts with severe cough of many causes, but larger amounts suggests bronchitis, bronchiectasis, tuberculosis, or primary lung cancer.[24]

Further workup may include labs, x-rays, and spirometry.[6]

Classification

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A cough can be classified by its duration, character, quality, and timing.[6] The duration can be either acute (of sudden onset) if it is present less than three weeks, subacute if it is present between three or eight weeks, and chronic when lasting longer than eight weeks.[6] A cough can be non-productive (dry) or productive (when phlegm is produced that may be coughed up as sputum). It may occur only at night (then called nocturnal cough), during both night and day, or just during the day.[6]

A number of characteristic coughs exist. While these have not been found to be diagnostically useful in adults, they are of use in children.[6] A barky cough is part of the common presentation of croup.[25] A staccato cough has been classically described with neonatal chlamydial pneumonia.[26]

Treatment

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The treatment of a cough in children is based on the underlying cause. In children half of cases go away without treatment in 10 days and 90% in 25 days.[27]

According to the American Academy of Pediatrics the use of cough medicine to relieve cough symptoms is supported by little evidence and thus not recommended for treating cough symptoms in children.[6] There is tentative evidence that the use of honey is better than no treatment or diphenhydramine in decreasing coughing.[28] It does not alleviate coughing to the same extent as dextromethorphan but it shortens the cough duration better than placebo and salbutamol.[28] A trial of antibiotics or inhaled corticosteroids may be tried in children with a chronic cough in an attempt to treat protracted bacterial bronchitis or asthma respectively.[6] There is insufficient evidence to recommend treating children who have a cough that is not related to a specific condition with inhaled anti-cholinergics.[29]

Because coughing can spread disease through infectious aerosol droplets, it is recommended to cover one's mouth and nose with the forearm, the inside of the elbow, a tissue or a handkerchief while coughing.[30]

Traditional medicine

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One of the pharmaceutical dosage forms in traditional medicine for treatment of coughs was linctus. A linctus is a medicine in the form of a syrup, taken to relieve coughs and sore throats. The linctus is a syrup that helps relieve dry coughs.[citation needed]

Epidemiology

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A cough is the most common reason for visiting a primary care physician in the United States.[6]

Other animals

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A coughing deer hind

Marine mammals such as dolphins and whales cannot cough.[31] Some invertebrates such as insects and spiders cannot cough or sneeze. Crocodiles can cough.[32] Domestic animals and vertebrates such as dogs and cats can cough, because of diseases, allergies, dust or choking.[33] In particular, cats are known for coughing before spitting up a hairball.[33]

In other domestic animals, horses can cough because of infections, or due to poor ventilation and dust in enclosed spaces.[34] Kennel cough in dogs can result from a viral or bacterial infection.

Deer can cough similarly to humans as a result of respiratory tract infections, such as parasitic bronchitis caused by a species of Dictyocaulus.[35]

References

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Further reading

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[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Cough

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from Grokipedia
A cough is a sudden, often involuntary, expulsion of air from the lungs through the mouth, serving as a protective mechanism to clear the airways of irritants, excess secretions, , and foreign particles. This is triggered by mechanical or chemical stimuli in the , which activate sensory nerves—primarily via the —sending signals to the to coordinate muscle contractions in the chest, diaphragm, and , building intrathoracic pressure exceeding 300 mm Hg before a rapid release of air at high speeds, up to 100 miles per hour. Coughing is a normal and essential function for maintaining airway patency and , but persistent or severe episodes can lead to complications such as , , rib fractures, or disrupted . Coughs are classified by duration into acute (lasting less than 3 weeks), subacute (3 to 8 weeks), and chronic (more than 8 weeks in adults or 4 weeks in children), with the latter often signaling an underlying medical condition rather than a . Acute coughs typically arise from self-limiting infections or irritants and resolve without intervention, while chronic coughs may persist due to multifactorial causes and require diagnostic evaluation. Accompanying symptoms can include production of (wet cough) or absence of it (dry cough), , wheezing, hoarseness, , or, in rare cases, (coughing up blood). Common causes of cough vary by type and include viral upper respiratory infections (such as the or , accounting for about 90% of acute cases), postinfectious airway inflammation, exacerbations, (GERD, implicated in up to 40% of chronic cases), and upper airway cough syndrome from . Other etiologies encompass (COPD), smoking-related , pertussis (), medications like ACE inhibitors, and less frequently, malignancies or infections such as . Epidemiologically, cough is the most frequent symptom prompting medical consultations, leading to up to 30 million outpatient visits annually , with a ranging from 5% to 40% influenced by factors like and environmental exposures. Medical attention is advised if a cough lasts longer than 2-3 weeks, produces bloody sputum, or is accompanied by high fever, difficulty breathing, severe weakness, weight loss, or chest pain, as these may indicate serious conditions requiring prompt assessment; be especially cautious with children and seek evaluation sooner if symptoms worsen. These are general guidelines and do not replace professional medical advice.

Presentation

Symptoms and Characteristics

A cough is defined as a sudden, often involuntary, forceful expulsion of air from the through the , serving as a protective mechanism to clear the airways of irritants, , or foreign particles. This reflex action originates from the stimulation of sensory receptors in the , triggering a coordinated muscular response involving the diaphragm, abdominal muscles, and to generate high-velocity . Coughs are broadly classified by their productivity: a dry or non-productive cough produces no and often feels irritating without relieving congestion, whereas a wet or productive cough expels or , aiding in clearing secretions from the lower airways. The characteristics of phlegm in productive coughs can provide preliminary clues to underlying causes, though colors are not definitive and professional diagnosis is essential. Clear or white phlegm is often associated with viral infections, allergies, or non-infectious irritants, where antibiotics are typically ineffective as the condition is not bacterial. Yellow or green phlegm may suggest a possible bacterial or viral infection, but it can occur in both and does not reliably distinguish between them; persistent colored phlegm warrants medical evaluation to rule out serious conditions. Coughs vary in timing and severity, which can provide clues to their nature. Nocturnal coughs predominate at night, often worsening when lying down due to increased drainage or , while postprandial coughs occur after meals, potentially linked to or reflux-related sensations. Severity ranges from mild, occasional episodes that minimally disrupt daily activities to paroxysmal coughs characterized by intense, uncontrollable bursts that may cause exhaustion or temporary breathlessness. These patterns can influence patient comfort and sleep, with paroxysmal forms sometimes leading to repeated hacking spells throughout the day or night. Coughs are further categorized by duration to guide clinical evaluation. Acute coughs last less than three weeks and are typically self-limiting, subacute coughs persist for three to eight weeks, often following an initial acute phase, and chronic coughs endure beyond eight weeks, requiring more thorough assessment. These classifications help distinguish transient responses from ongoing issues without implying specific origins. Patients often experience associated symptoms alongside the cough itself, such as a from repeated , chest or tightness due to muscular strain, and wheezing indicating narrowed airways. Sensorily, coughs are commonly preceded by a or itching sensation in the , accompanied by an intense urge to cough that builds until expulsion provides temporary relief. This urge-to-cough sensation, distinct from , can feel like an irritating scratch or paraesthesia localized to the or upper airways.

Complications

Coughing, particularly when prolonged or forceful, can lead to a variety of complications arising from the mechanical forces generated during the act. These include musculoskeletal injuries such as fractures, which occur due to the repetitive stress on the thoracic cage, especially in individuals with or during severe coughing episodes. Muscle strains in the chest wall, , or diaphragm are also common, while hernias—such as inguinal, hiatal, or types—may develop from increased intra-abdominal pressure. Cardiovascular effects stem from transient elevations in intrathoracic pressure, which can cause cough syncope—a temporary loss of due to reduced cerebral blood flow—or arrhythmias like bradyarrhythmias. Subconjunctival hemorrhage, presenting as painless red spots in the eyes from ruptured vessels, is another frequent minor complication. Respiratory complications often involve worsening of pre-existing conditions, such as exacerbations triggered by the irritative effects of coughing, or more severe issues like in cases of underlying lung fragility. Gastrointestinal disturbances include vomiting induced by intense coughing bouts and aggravation of (GERD) due to repeated pressure on the lower esophageal sphincter. Among rarer events, may result from weakened muscles strained by coughing, particularly in older adults or those with prior incontinence. Over the long term, persistent coughing contributes to fatigue and sleep disruption, impairing overall and leading to burdens like anxiety over health. lasting more than eight weeks heightens the risk for these complications.

Pathophysiology

Cough Reflex

The cough reflex is a vital protective mechanism that expels irritants, , and foreign particles from the through coordinated neural and muscular activity. It involves a comprising sensory detection, central processing, and motor response, triggered by stimulation of specialized receptors in the airways. This reflex ensures airway clearance and prevents aspiration, thereby reducing the risk of complications such as . The reflex proceeds in three distinct phases. The inspiratory phase begins with a deep inhalation, where the opens and the diaphragm along with contract to draw air into the lungs, typically reaching about 50% of . This is followed by the compressive phase, during which the and close, and abdominal, intercostal, and diaphragm muscles contract to build intrathoracic up to 300 mm Hg. Finally, the expiratory phase involves relaxation of the , allowing forceful expulsion of air at velocities up to 100 km/h (28 m/s), which dislodges and ejects material from the airways. Afferent signals initiating the reflex arise from cough receptors, including rapidly adapting receptors, slowly adapting stretch receptors, and C-fibers, located primarily in the , , trachea, and bronchi. These receptors detect mechanical irritation, chemical stimuli, or and transmit impulses via branches of the , such as the superior laryngeal and recurrent laryngeal nerves, to the . Central integration occurs in the , where the nucleus tractus solitarius receives and processes afferent inputs, coordinating with the medullary cough center and adjacent nuclei like the nucleus retroambigualis and . This processing determines whether the stimulus exceeds the cough threshold, integrating sensory data to generate an appropriate response pattern. Efferent output from the central cough center travels via the vagus, phrenic, and spinal motor nerves to activate key muscles, including the diaphragm for inspiration, laryngeal muscles for glottis control, and abdominal and internal intercostal muscles for expiration. This coordinated activation ensures the sequential phases of the reflex unfold efficiently. The threshold and sensitivity of the cough reflex vary; in normal states, it responds to significant irritants, but hypersensitivity can occur in conditions like inflammation, making the reflex more easily triggered, while hyposensitivity impairs clearance. Women generally exhibit higher sensitivity compared to men. Overall, the plays an essential protective role by clearing excessive secretions, foreign bodies, and pathogens from the airways, thereby maintaining respiratory and preventing or infection.

Neural and Mechanical Mechanisms

The neural mechanisms underlying cough involve both peripheral and central processes that amplify the in response to airway . Peripheral occurs primarily through the of transient receptor potential vanilloid 1 () receptors expressed on C-fiber nociceptors in the airway mucosa and vagal afferent nerves. These receptors detect chemical irritants, such as or acid, leading to heightened sensitivity and enhanced cough responses by depolarizing sensory neurons and releasing neuropeptides like . Similarly, (ATP), released from damaged epithelial cells during inflammation, sensitizes airway nerves via P2X3 receptors, which are purinergic ion channels on vagal afferents that facilitate rapid calcium influx and neuronal firing, contributing to tussive hypersensitivity. These peripheral changes lower the threshold for cough initiation, transforming innocuous stimuli into potent triggers. Central sensitization further modulates cough by altering processing in the and higher cortical regions, culminating in cough hypersensitivity syndrome (CHS), a condition characterized by exaggerated neural responsivity to diverse stimuli affecting the airways, , and . In the , particularly the nucleus tractus solitarius and parabrachial nucleus, incoming vagal signals undergo integration and amplification through , including , which sustains heightened excitability. Cortical involvement, via areas like the insula and , adds voluntary control and emotional modulation, where reduced inhibitory activity can perpetuate chronic coughing by failing to dampen reflexive outputs. This central dysregulation in CHS often persists beyond initial insults, reflecting a shift from protective reflex to maladaptive hypersensitivity. Mechanically, cough generates explosive forces to clear airways, with expiratory airflow velocities reaching up to 60 miles per hour (approximately 27 meters per second) during the expulsion phase, driven by rapid glottal opening and subglottic pressure buildup. These high velocities produce substantial shear stresses on the airway walls, estimated at up to 14 pascals in simulations of peak flows, which dislodge mucus and pathogens by creating turbulent flow and direct mechanical abrasion. Such biomechanics underscore cough's efficacy as a clearance mechanism but also risk airway trauma in hypersensitive states. Recent research from 2024 and 2025 highlights and vagal neuropathy as key drivers in refractory , where proinflammatory cytokines like IL-1β and TNF-α infiltrate vagal ganglia, promoting demyelination and ectopic firing in afferent nerves. In post-infectious cases, particularly following , viral neurotropism—direct invasion of neural tissues by the —exacerbates this through persistent microglial and disrupted vagal signaling, leading to prolonged . differences influence these pathways, with prevalence approximately twice as high in females, attributed to estrogen's enhancement of expression and in vagal and cortical circuits during and beyond. Inhibitory mechanisms counteract excessive coughing via endogenous opioids and in the . Endogenous opioids, such as enkephalins, bind mu and kappa receptors on cough-related neurons in the nucleus tractus solitarius, hyperpolarizing cells to suppress reflex arcs and reduce central drive. GABA, acting through GABAB receptors on presynaptic terminals, inhibits release from excitatory afferents, providing tonic suppression that diminishes in CHS due to receptor downregulation. These pathways maintain balance, preventing overactivation while preserving defensive coughing.

Causes

Infectious Causes

Infectious causes of cough primarily involve microbial pathogens that invade the , triggering irritation of the through and production. These infections range from self-limiting upper respiratory illnesses to severe lower respiratory tract diseases, with viruses accounting for the majority of acute cases. Viral infections are the most common infectious etiology of cough, often presenting as acute respiratory illnesses. The , primarily caused by rhinoviruses, typically features a dry or productive cough lasting 1-3 weeks, accompanied by and . viruses induce a more severe cough, frequently with fever, myalgias, and , which can persist for several weeks in uncomplicated cases. (RSV) is a leading cause of cough in infants and young children, resulting in with wheezing and respiratory distress, though it can affect adults as well. Severe acute respiratory syndrome coronavirus 2 (), responsible for , commonly manifests with a dry cough during acute , and post-acute sequelae include in over 30% of cases, as reported in cohort studies from 2023-2025. Bacterial infections contribute to cough in both acute and chronic settings, often following viral predisposition or occurring independently. Pertussis, caused by , produces characteristic paroxysmal coughing fits ending in inspiratory whoops, particularly severe in unvaccinated individuals. Pneumonia due to features productive cough with purulent sputum, chest pain, and fever, representing a major cause of community-acquired lower respiratory infection. Tuberculosis, induced by , leads to lasting over three weeks, often with in advanced pulmonary disease. Fungal infections are less common but significant in immunocompromised hosts, where they can cause invasive disease with prominent cough. , resulting from species , manifests as with in conditions like or . Parasitic infections rarely cause cough but can involve the lungs through larval migration. , due to , may lead to cough during the pulmonary phase of migration, typically in endemic regions with poor . Most respiratory infections spread via respiratory droplets from coughing or sneezing, with many exhibiting seasonal peaks in winter due to indoor crowding and lower facilitating viral survival. Post-infectious cough can persist for up to 8 weeks after viral resolution, attributed to heightened airway and .

Non-Infectious Causes

Non-infectious causes of cough encompass a range of intrinsic respiratory, systemic, and neurological conditions that trigger the without involvement of microbial pathogens. These etiologies often stem from chronic , mechanical irritation, or structural abnormalities in the airways or related systems, leading to persistent or recurrent coughing that can significantly impact . Common mechanisms include heightened airway sensitivity or direct stimulation of cough receptors, distinguishing them from acute infectious processes. Reactive airway diseases represent a primary category of non-infectious cough triggers. In cough-variant , patients present with a dry, non-productive cough as the predominant symptom, often worsening at night or with exercise, due to eosinophilic inflammation and without typical wheezing. (COPD) exacerbations can also manifest as cough, particularly in smokers or those with , where mucus hypersecretion and airflow limitation irritate the airways, though this is distinct from infectious flares. Gastroesophageal reflux disease (GERD) frequently causes cough through microaspiration of into the and upper airways, leading to chemical irritation and reflex coughing, especially in positions. This is supported by studies showing improvement with inhibitors in GERD patients with , highlighting the role of . Cardiac conditions, such as congestive heart failure, provoke cough via that accumulates fluid in the alveoli, stimulating and often presenting nocturnally as orthopnea-associated coughing. Allergic mechanisms contribute to cough through from , where inflammatory mediators cause and drainage that irritates the and triggers the . This is particularly evident in seasonal allergies, with release exacerbating upper airway sensitivity. Neoplastic causes include , where tumors directly compress or invade bronchi, eliciting persistent cough often accompanied by , and that impinge on the or major airways, leading to irritative symptoms. Habit cough, also known as psychogenic cough, typically occurs in children following a resolved upper respiratory illness and manifests as a repetitive, tic-like barking that resolves with distraction but persists during wakefulness. It is linked to psychological factors rather than organic , with behavioral therapies proving effective. Neurogenic cough arises from irritation, such as post-surgical complications or tumors affecting the , resulting in chronic, refractory coughing due to aberrant neural signaling. Neural serves as a common pathway in many of these conditions, amplifying cough responses to otherwise innocuous stimuli.

Environmental and Iatrogenic Causes

Environmental causes of cough encompass exposures to airborne irritants that provoke airway and reflexive expulsion of foreign material. , particularly from particulate matter (PM), smoke, and , directly irritates the , leading to acute and as a protective response. Fine particulate matter (PM2.5) and penetrate deep into the lungs, causing and hypersecretion that manifest as persistent coughing, especially in urban environments with high pollution levels. Historical episodes of severe urban , such as those involving heavy smoke and industrial emissions, have been linked to sharp rises in respiratory irritation and cough prevalence, exacerbating morbidity in vulnerable populations. Occupational exposures represent a significant subset of environmental triggers, where prolonged contact with dust, fumes, and chemicals induces irritant-mediated cough and related conditions. Workers in industries like , , and face elevated risks from inhaling silica , metal particles, or volatile organic compounds, which inflame the bronchi and provoke as an early symptom. For instance, exposure to cement has been associated with increased cough and production due to mechanical and chemical reactivity in the airways. Irritant-induced often begins with non-productive cough following high-level exposures, progressing to wheezing and dyspnea if unaddressed. Tobacco smoking stands out as a pervasive environmental irritant, driving the development of chronic bronchitis through repeated exposure to , , and combustion byproducts that damage ciliary function and stimulate . This results in a productive cough that persists for at least three months annually over two consecutive years, serving as a hallmark of smoker's cough. The irritants in not only initiate but also perpetuate airway remodeling, making cough a daily occurrence for many long-term smokers. Climatic factors, including cold air and seasonal allergens, can trigger cough by altering airway temperature, humidity, or allergen load. Inhalation of , dry air during winter months cools and dehydrates the respiratory mucosa, heightening sensitivity to irritants and inducing reflex cough, particularly in individuals with underlying hyperreactivity. Seasonal shifts amplify this through or mold spores, which deposit in the airways and provoke allergic cough during peak bloom periods, often worsening in polluted or changing climates. Foreign body aspiration, often from choking on small objects like food or toys, abruptly initiates intense cough as the body's mechanism to clear the obstruction from the trachea or bronchi. This event is predominantly reported in children aged 1 to 3 years, where exploratory behaviors increase aspiration risks, with cough being the most common initial symptom in over 80% of cases. Delayed can lead to protracted cough mimicking chronic respiratory issues. Iatrogenic causes primarily involve medications that inadvertently stimulate cough pathways. (ACE) inhibitors, such as lisinopril, commonly prescribed for and , elevate levels by inhibiting its degradation, resulting in a dry, non-productive cough affecting 5-20% of users, typically emerging within weeks to months of initiation. This side effect arises from bradykinin-induced airway hypersensitivity and is more prevalent in women and nonsmokers. Switching to alternative agents like angiotensin receptor blockers often resolves the cough.

Diagnostic Approach

History and Examination

The initial evaluation of cough begins with a detailed to characterize the symptom and identify potential etiologies. Key elements include the onset (sudden or gradual), duration (acute less than 3 weeks, subacute 3 to 8 weeks, or chronic more than 8 weeks in adults), and associated features such as triggers like lying down or bending over, which may suggest (GERD). Inquiries should cover characteristics, including color (e.g., purulent suggesting ) and volume, as well as history, occupational or environmental exposures (e.g., dust, chemicals, low humidity, pet allergens such as cat dander, or travel to endemic areas), and medication use such as () inhibitors, which are common iatrogenic causes. For dry cough, exacerbation after pet contact accompanied by symptoms like sneezing, runny nose, or itchy eyes suggests allergy, whereas isolated throat dryness improving with humid environments indicates dry air effects; assessing response to allergen avoidance or humidification can aid differentiation, with possible coexistence. Red flags in the history warrant urgent evaluation to rule out serious conditions. These include , unintentional , recurrent , , fever, shortness of breath, wheezing, chest pain, difficulty breathing, coughing up thick green or yellow phlegm, significant mucus production, or symptoms suggestive of or (TB), such as prolonged cough in smokers or those with . Cough persisting beyond 1-3 weeks without improvement, exceeding 8 weeks (chronic), or failing to respond to home care also prompts evaluation. Other concerning features encompass swelling, fainting, or hoarseness, which may indicate cardiac involvement, airway obstruction, or laryngeal involvement; sudden or severe cough, particularly with underlying conditions such as or (COPD), requires immediate urgent care or emergency assessment. Physical examination complements the history by focusing on non-invasive assessments. Vital signs should be checked for , fever, or hypoxia indicating systemic involvement. Lung may reveal wheezes (suggesting or ), crackles (indicating interstitial disease or infection), or diminished breath sounds (possible or consolidation). Examination of the , , and (ENT) structures is essential to identify , nasal polyps, or sinus tenderness associated with upper airway cough syndrome. Abdominal can detect epigastric tenderness or relevant to GERD or other gastrointestinal contributors. Validated questionnaires aid in quantifying cough severity and its impact on daily life. The Leicester Cough Questionnaire (LCQ), a 19-item tool assessing physical, psychological, and social domains over the past 2 weeks or 10 days, is widely used to measure cough-related , with scores ranging from 3 to 21 (lower scores indicating greater impairment). Age-specific considerations are crucial, as cough patterns differ between pediatric and adult patients. In children, is defined as lasting more than 4 weeks, and history should probe for barking or brassy quality suggestive of or , paroxysmal episodes resembling pertussis, or wet productive cough indicating protracted bacterial bronchitis; red flags include or digital clubbing. Parents should be especially cautious with children and seek medical attention if the cough lasts longer than 1-2 weeks, is accompanied by high fever, difficulty breathing, coughing up blood, or severe weakness, disrupts sleep at night, is severe, accompanies wheezing or breathing difficulty, poor appetite, or recurs frequently; these are general guidelines that do not replace professional medical evaluation, and consultation with a pediatrician or pulmonologist is recommended for persistent or alarming symptoms, potentially including tests like chest X-ray to rule out pneumonia or allergy testing for asthma. Physical exam in emphasizes growth parameters and may reveal chest wall deformities. In adults, cough often relates to syndromes, with higher prevalence in middle-aged women, and history focuses on chronic irritant exposures.

Investigations and Tests

Investigations and tests for cough focus on objective assessments to identify underlying causes, guided by clinical history to prioritize appropriate modalities. Recent guidelines, including the 2025 WAO-ARIA consensus, emphasize a treatable traits approach for refractory cases, incorporating assessments for cough hypersensitivity alongside traditional tests. Chest radiography serves as an initial imaging tool, recommended for evaluating persistent cough to detect structural abnormalities such as pneumonia, lung tumors, or aspirated foreign bodies, with guidelines emphasizing its role in excluding serious pathology before further testing. Pulmonary function tests, particularly , are essential for assessing airflow obstruction in suspected cases of or (COPD), measuring forced expiratory volume in one second (FEV1) and forced (FVC) to quantify obstruction with a below 0.7 indicating potential . analysis complements this by enabling to identify infectious agents like or mycobacteria in productive cough, while cytological examination detects malignant cells suggestive of , particularly in smokers or those with risk factors. For cough linked to (GERD), ambulatory quantifies acid exposure over 24-48 hours to confirm reflux episodes correlating with symptoms, often combined with esophageal manometry to evaluate motility disorders that may contribute to reflux-induced cough. provides direct visualization of the airways, allowing or removal of foreign bodies, tumors, or inflammatory lesions, and is indicated when imaging suggests endobronchial pathology or cough persists despite initial evaluations. Allergy testing, such as prick tests, identifies IgE-mediated sensitization to aeroallergens in cases of upper airway cough due to , where positive wheal responses greater than 3 mm indicate relevant triggers like or dust mites. Emerging protocols for cough , a common feature in refractory , utilize inhalation challenges to measure tussive response thresholds, with 2024 studies standardizing dose-response endpoints to differentiate from healthy controls, aiding in targeted neuromodulator therapy selection.

Classification of Cough

Coughs are classified primarily by duration, productivity, and etiology to facilitate and management strategies. This helps clinicians distinguish between self-resolving episodes and those requiring further evaluation, as the underlying mechanisms and implications vary significantly across categories. Recent 2025 reviews highlight the integration of hypersensitivity assessments in classifications for unexplained cases.

By Duration

Cough duration is a foundational classification criterion, dividing cases into acute, subacute, and chronic based on persistence. Acute cough lasts less than 3 weeks and is often associated with viral upper respiratory infections, resolving without specific intervention in most cases. Subacute cough persists for 3 to 8 weeks, frequently representing a post-infectious phase following resolution of the initial acute illness, such as after viral . endures beyond 8 weeks in adults or 4 weeks in children and is typically multifactorial, involving persistent inflammation, neural sensitization, or underlying chronic conditions like or gastroesophageal reflux disease (GERD).

By Productivity

Productivity refers to whether the cough produces or , influencing its physiological role and clinical assessment. A productive cough involves expectoration of secretions, which aids in clearing the airways of pathogens, irritants, or excess , commonly seen in infections or (COPD). The color of the sputum can provide diagnostic clues to the underlying etiology, though it is not definitive and should be interpreted in clinical context. Clear or white sputum is often associated with viral infections or allergies, while yellow or green sputum may suggest a bacterial infection but can also occur in viral cases due to immune cell activity. In contrast, a non-productive or dry cough lacks noticeable and often feels irritating or tickling, stemming from heightened airway sensitivity without significant secretion buildup, as in early viral infections or allergic responses. This distinction guides symptomatic relief, emphasizing suppression for dry coughs while supporting clearance for productive ones.

By Etiology

Etiological localizes the cough to upper airway, lower airway, or non-respiratory origins, reflecting the anatomical site of or dysfunction. Upper airway causes, collectively termed upper airway cough (UACS), include from or , where mucus drainage triggers laryngeal . Lower airway etiologies involve bronchial or parenchymal issues, such as or chronic , where or provokes cough through direct airway stimulation. Non-respiratory causes extend beyond the lungs, encompassing GERD, where acid sensitizes esophageal and vagal nerves, or cardiac conditions like congestive heart failure, leading to pulmonary congestion and cough.

Special Classifications

Refractory chronic cough, often unexplained after standard evaluations, is increasingly recognized as cough hypersensitivity (CHS), characterized by exaggerated neural responses to innocuous stimuli like odors or temperature changes, independent of identifiable structural disease. This condition highlights a sensory neuropathy in the arc, affecting up to 40% of patients.

Prognostic Classifications

Prognostically, coughs are differentiated as self-limiting or progressive to predict outcomes and urgency. Self-limiting coughs, typical of acute viral etiologies, resolve spontaneously within weeks without long-term sequelae. Progressive coughs, often chronic and linked to conditions like or untreated , indicate worsening underlying disease and poorer if unaddressed.

Treatment

Acute Cough Management

Acute cough, defined as lasting less than three weeks and frequently caused by viral upper respiratory infections, is generally self-limiting and managed through supportive measures aimed at symptom relief rather than curing the underlying cause. For acute coughs, distinguishing between productive (wet) and non-productive (dry) types can guide management. Productive coughs involve the expulsion of phlegm or mucus, where the color can provide clues to the underlying cause. Clear or white phlegm often indicates a viral infection or allergies, in which case antibiotics are ineffective and unnecessary, as they do not treat viral etiologies. Yellow or green phlegm may suggest a bacterial infection but can also occur in viral cases, and antibiotics should only be used if bacterial etiology is confirmed. Maintaining hydration by drinking plenty of fluids, such as water, herbal teas, or warm lemon water, helps thin mucus secretions, promoting easier clearance from the airways, while using a humidifier to add moisture to the air can soothe irritated tissues and loosen phlegm for more effective coughing. Cool-mist humidifiers are preferred, especially in households with children, as they reduce the risk of burns and should be maintained at 40-50% humidity with daily cleaning to prevent bacterial growth. Steam inhalation or steamy showers can provide similar moistening effects for the airways. These non-pharmacologic approaches are foundational for managing productive coughs associated with acute conditions. Over-the-counter options for productive coughs include expectorants and mucolytics such as guaifenesin (e.g., Mucinex), ambroxol (30 mg three times daily), acetylcysteine (200–600 mg per day in divided doses), carbocisteine (750 mg two to three times daily), and bromhexine (8–16 mg three times daily). These agents reduce mucus viscosity and facilitate expectoration, with particular application in adolescents aged 12 years and older for symptomatic management of productive cough. Dosing should follow product instructions or physician guidance. For soothing irritation, particularly in children over 1 year, honey has demonstrated efficacy; a 2023 systematic review of randomized controlled trials found low-quality evidence that it reduces cough frequency and severity more effectively than placebo or standard cough medications, while also improving sleep, though high-quality trials are needed for confirmation. Honey is not recommended for children under 1 year due to the risk of infant botulism. Antitussives such as dextromethorphan are suitable for suppressing dry, non-productive coughs by blunting the cough reflex, with typical dosing of 10-20 mg every 4-6 hours in adults, but they are not recommended for children under 6 years due to limited efficacy and safety concerns. Antitussives, including codeine and butamirate, are contraindicated in productive cough as they suppress the cough reflex and can impede sputum clearance, potentially leading to mucus retention and complications. Complementary home remedies for dry cough include sucking on throat lozenges or hard candies containing menthol or peppermint to increase saliva production and ease irritation, and gargling with warm salt water (½ teaspoon salt in 8 ounces of water) several times a day to reduce inflammation. For productive coughs likely due to viral causes (e.g., white phlegm), expectorants and mucolytics such as guaifenesin, ambroxol, acetylcysteine, carbocisteine, and bromhexine, along with humidifiers, hydration, and other supportive measures, are recommended as first-line remedies. Supportive measures include abundant warm fluids, air humidification, and avoidance of smoking or passive smoking exposure. Caveats include consulting a healthcare provider before using OTC medications in children under 12 or if symptoms worsen, and for adolescents, consultation with a pediatrician, therapist, or pulmonologist is essential due to the risks of self-medication; seeking medical advice if the cough persists or is accompanied by concerning symptoms. Antibiotics are applied only upon confirmation of bacterial infection by a physician. Avoiding environmental irritants is crucial, including immediate smoking cessation if applicable, as tobacco smoke exacerbates airway inflammation and prolongs symptoms, and removing exposure to allergens or pollutants can prevent worsening of the cough. Antibiotics are not routinely indicated for acute cough, which is predominantly viral, but should be considered only upon confirmation of a bacterial etiology, such as in suspected pertussis cases where macrolides like azithromycin are preferred to reduce transmission and severity if initiated early. Medical evaluation is warranted if the cough persists beyond three weeks, or if accompanied by red flags such as fever above 100.4°F, shortness of breath or dyspnea, bloody mucus, or wheezing, as these may signal complications like pneumonia requiring prompt intervention.

Chronic Cough Management

Management of chronic cough begins with identifying and treating underlying etiologies, as this forms the cornerstone of a stepwise approach guided by cough classification. For cough-variant asthma, inhaled corticosteroids are recommended to reduce airway inflammation and suppress symptoms, often combined with bronchodilators for optimal control. In cases linked to gastroesophageal reflux disease (GERD), proton pump inhibitors (PPIs) such as omeprazole are trialed for 2-3 months to alleviate acid-related irritation of the esophagus and airways. Postnasal drip syndrome, commonly due to rhinitis, is addressed through lifestyle measures including saline nasal irrigation, avoidance of irritants, and intranasal corticosteroids to decrease mucus production and drainage. When underlying causes are addressed but cough persists, behavioral interventions like speech-language therapy are employed to suppress the cough reflex and reduce hypersensitivity. This therapy involves techniques such as the "sniff-twitch-swallow" method, where patients learn to sniff gently, twitch the soft palate, and swallow to interrupt the urge-to-cough cycle, alongside relaxed breathing exercises to desensitize laryngeal triggers. Evidence supports its efficacy in refractory cases, with improvements in cough frequency and quality of life observed in clinical trials. For neuropathic or refractory chronic cough characterized by central sensitization, low-dose neuromodulators are used off-label to modulate aberrant neural pathways. Amitriptyline at 10-25 mg daily or gabapentin at 300-900 mg daily can reduce cough severity by targeting vagal nerve hypersensitivity, with systematic reviews confirming benefits in select patients unresponsive to standard therapies. These agents are titrated slowly to minimize side effects like drowsiness. Airway clearance strategies are integrated for productive chronic cough, particularly in those with mucus hypersecretion. Physiotherapy techniques, including postural drainage and breathing exercises, facilitate expectoration, while mucolytics such as N-acetylcysteine (600 mg orally twice daily), ambroxol, carbocisteine, and bromhexine help thin secretions to improve clearance, though routine aerosolized use is not universally recommended. These interventions are tailored based on sputum characteristics and patient tolerance. These interventions are tailored based on sputum characteristics and patient tolerance. Refractory chronic cough warrants multidisciplinary referral to specialized cough clinics, where pulmonologists, otolaryngologists, speech therapists, and gastroenterologists collaborate to refine diagnostics and personalize treatment. These clinics employ comprehensive evaluations to manage complex cases, improving outcomes through integrated care. Ongoing monitoring is essential to assess treatment response and cough burden. Patients maintain cough diaries to track frequency, triggers, and severity, while validated quality-of-life tools like the Leicester Cough Questionnaire (LCQ) or Severity of Chronic Cough Diary (SCCD) quantify impacts on daily functioning and psychological well-being, guiding adjustments in therapy.

Emerging Therapies

Emerging therapies for refractory chronic cough target the neural hypersensitivity underlying the condition, focusing on afferent nerve signaling pathways in the airways and vagus nerve. These interventions aim to interrupt aberrant cough reflexes rather than addressing underlying causes like inflammation or infection. Recent advancements from 2023 to 2025 emphasize selective antagonists and non-pharmacological tools, offering hope for patients unresponsive to conventional treatments. P2X3 receptor antagonists represent a breakthrough in pharmacological management by blocking purinergic signaling in airway sensory neurons, which contributes to cough hypersensitivity. Gefapixant, the first agent in this class, received European Union approval in September 2023 for treating refractory chronic cough in adults, following positive results from phase 3 trials demonstrating a statistically significant reduction in 24-hour objective cough frequency of approximately 18-20% compared to placebo at 45 mg twice daily. As of November 2025, gefapixant has not received FDA approval in the United States. Despite its modest efficacy in objective measures, gefapixant improved patient-reported outcomes in cough severity and urge-to-cough, though common side effects include taste disturbances affecting up to 60% of users. Camlipixant, a next-generation P2X3 antagonist, is in phase 3 trials, with data from the SOOTHE phase 2b study showing a 34% placebo-adjusted reduction in 24-hour cough frequency at doses of 50 mg and 200 mg twice daily, alongside improvements in cough severity scores and an acceptable safety profile. TRPV1 modulators, which target transient receptor potential vanilloid 1 channels on sensory afferents, are under investigation to desensitize cough-evoking nerves in the airways. These agents, including inhaled or oral formulations, aim to reduce hypersensitivity by downregulating TRPV1-mediated responses to irritants, building on preclinical evidence that TRPV1 activation drives chronic cough reflexes. Although early clinical trials, such as those with XEN-D0501, did not meet efficacy endpoints for refractory cough, ongoing investigational efforts explore combination therapies or novel agonists for sustained desensitization without the side effects of hyperthermia or cardiovascular risks seen in first-generation compounds. Digital therapeutics have gained traction as accessible, non-invasive options for behavioral modification in chronic cough. Internet-based behavioral cough suppression therapy (IBCST) delivers guided exercises and monitoring via online platforms to retrain cough reflexes and reduce awareness of the urge-to-cough. A 2025 randomized controlled trial showed clinically significant improvements in cough-related quality of life (Leicester Cough Questionnaire scores improved by a mean of 3.74-4.1 points in 72-76% of participants) and trends toward reduced cough severity, with high user adherence due to its remote format. Neural signaling inhibitors, including biologics directed at vagal pathways, are in early-stage development to modulate central and peripheral cough circuits. These agents target neuropeptides or cytokines involved in vagal afferent hypersensitivity, with preclinical models showing suppression of cough-like reflexes through inhibition of NTS neurons. Early 2025 trials of monoclonal antibodies against TRPV1-upstream mediators reported preliminary reductions in cough sensitivity, though larger studies are needed to confirm efficacy and safety in humans. Genomic studies in 2024 identified variants in neuronal ion channels, such as KCNA10, contributing to cough hypersensitivity in chronic dry cough. Future gene therapy approaches may target such genetic factors, drawing on preclinical advances in inhalation delivery of nucleic acid therapies to silence hypersensitive genes like those in TRP channels for long-term desensitization of cough afferents without systemic effects. Despite these innovations, access to emerging therapies remains challenged by high costs and limited availability, as discussed at CHEST 2025, which highlighted digital interventions for broader equity and the need for reimbursement pathways for approved agents like gefapixant in high-income settings. Ongoing trials and policy discussions aim to address disparities, particularly in low-resource regions where neural-targeted treatments could transform management of refractory cases.

Epidemiology

Global Prevalence

Acute cough, typically lasting less than three weeks and often resulting from viral upper infections, affects a substantial portion of the global annually, with estimates ranging from 10% to 33% in general studies. In settings, acute cough accounts for a significant share of visits, representing up to 50% of consultations for respiratory symptoms in some Western countries, predominantly driven by self-limiting viral etiologies. Chronic cough, defined as persisting for eight weeks or longer in adults, has a global of approximately 9.6%, with rates varying widely from 2% to 18% across regions and populations. This condition is more prevalent among women, who comprise about two-thirds of affected individuals, and reaches up to 10-12% in parts of the and . Geographic variations in cough prevalence reflect environmental and infectious disease burdens, with higher rates observed in developing countries where and (TB) contribute significantly; for instance, prevalence can exceed 15% in certain South Asian areas like due to these factors. In contrast, overall rates are lower in at around 4.4%, though pollution-related exacerbations elevate local incidences. TB-endemic regions, particularly in and , show elevated cough reporting linked to pulmonary infections. Cough incidence peaks in specific age groups and demographics, with children experiencing higher rates from conditions like and pertussis, which cause acute barking or episodes often requiring medical attention. In the elderly, prevalence rises due to (COPD), with frequent cough reported in up to 9.3% of older adults, compounded by age-related comorbidities. Gender disparities persist, with chronic forms disproportionately affecting women across age groups. The economic burden of cough is considerable, encompassing direct healthcare costs for consultations, diagnostics, and treatments, as well as from and reduced productivity; studies indicate that patients incur substantially higher resource utilization, with mean annual costs per individual exceeding £1,600 in high-income settings, contributing to a global estimate in the tens of billions annually prior to when scaled by .

Post-Pandemic Trends

Following the COVID-19 pandemic, chronic cough has emerged as a significant sequela in recovered patients, with prevalence exceeding 30% in certain cohorts, particularly those with initial severe disease. A 2023 study in the Journal of the American Medical Association (JAMA) highlighted this trend, attributing persistent cough to neurologic dysfunction rather than primary respiratory pathology, as SARS-CoV-2's interaction with vagal nerve pathways and peripheral receptors like P2X2/P2X3 heightens cough reflex sensitivity. This neurologic basis has led to increased refractory cases, where cough resists standard treatments, driven by neuroinflammation and the virus's neurotropism, as evidenced by 2024 research in Clinical Microbiology Reviews. In the context of long COVID, cough affects 10-20% of cases, often persisting for 1-2 years post-infection, contributing to subtypes characterized by multisystem involvement. Recent data from a cohort study in BMC Infectious Diseases reported cough in 41.2% of long COVID patients at follow-up, with durations extending beyond 12 months in hospitalized survivors, where 29.5% still experienced symptoms. Emerging variants, such as the Nimbus strain (NB.1.8.1), have been associated with prolonged respiratory symptoms including cough, alongside hallmark features like severe , exacerbating persistence in vulnerable populations. Global of cough has shifted post-2020, with heightened respiratory rates fueling outbreaks; for instance, 2025 surveillance indicated elevated cough incidence during surges of , RSV, and , reaching up to 39% in affected communities per studies. Risk factors for cough persistence include pre-existing and production, which independently predict long-term symptoms in post-COVID cohorts, as identified in a 2024 Respiratory Medicine analysis. has mitigated these trends, with 2025 data showing reduced severe and persistent cough in vaccinated individuals, lowering risk by up to 32% for airway diseases through attenuated viral neurotropism.

Traditional Medicine

Herbal and Folk Remedies

Throughout history, herbal and folk remedies have been employed to alleviate cough symptoms, with ancient texts documenting their use. The , an Egyptian medical document dating to around 1550 BCE, describes as a remedy for coughs and ailments, often combined with other natural substances for soothing effects. Similarly, ancient Egyptian practices utilized 's healing properties to treat respiratory issues, reflecting early empirical observations of its benefits. Thyme and ivy leaf extracts are among the most studied herbal remedies for cough relief, valued for their mucolytic and antitussive properties that help thin and reduce coughing frequency. These extracts work by relaxing bronchial smooth muscles and promoting expectoration, as demonstrated in clinical studies showing reduced cough fits by up to 68% compared to . A 2021 further confirmed their efficacy in acute upper infections, particularly for adults experiencing bronchitis-related cough. Honey, often mixed with lemon, serves as a traditional soothing remedy for cough, leveraging honey's antibacterial and demulcent qualities to coat the throat and suppress irritation. Systematic reviews of RCTs indicate that honey provides modest relief for acute cough in children over one year old, reducing nighttime coughing and improving sleep more effectively than usual care or over-the-counter options; current accumulating evidence suggests that honey might have a role in treating cough and cold in children, a recommendation made by the World Health Organization. Lemon enhances this by providing vitamin C and aiding in mucus clearance, though evidence for the combination specifically remains supportive rather than definitive. Common folk remedies for dry cough include consuming 1.5–2 liters daily of warm fluids such as herbal teas with linden blossom, thyme, or sage to moisten mucous membranes, alongside honey (1–2 teaspoons, pure or in tea) for throat soothing. Additional common preparations encompass ginger tea or fresh ginger juice for its soothing and anti-inflammatory effects, turmeric milk (often consumed at night) for its anti-inflammatory properties, gargling with warm salt water to reduce throat irritation, and steam inhalation to aid in loosening and expelling phlegm. Adequate hydration through increased fluid intake and sufficient rest are also recommended to support recovery and prevent dehydration. Humidifying room air via humidifiers, bowls of water, or damp cloths, particularly at night, and sucking on sugar-free lozenges with Icelandic moss or marshmallow to stimulate saliva production are also recommended. Avoiding irritants like smoke, dust, strong scents, and cold air, while ventilating without drafts, supports symptom relief. Traditional options include onion juice (from chopped onion steeped in honey or sugar) and warm chest wraps (e.g., with hot potatoes or quark). Steam inhalation over hot water with salt or chamomile is used to moisten airways and facilitate expectoration but has limited evidence for efficacy and carries burn risks, especially for children and asthma patients. In traditions, ginger and are utilized for their effects to mitigate cough associated with colds and inflammation. Common preparations include ginger tea or juice and turmeric milk (haldi doodh) to alleviate airway irritation and reduce inflammation. Ginger's active compounds, such as , exhibit and expectorant actions, helping to reduce airway as noted in traditional texts and supported by modern reviews of use in respiratory symptom management. , containing , is similarly prescribed in for its potent properties, which may alleviate cough by inhibiting inflammatory mediators in the . A 2023 review highlights their combined role in Ayurvedic formulations for symptoms, including cough, with preliminary evidence from RCTs showing reduced inflammation markers. Overall, systematic reviews of RCTs demonstrate modest efficacy for these herbal remedies in acute cough, with thyme-ivy combinations and showing the strongest evidence for symptom reduction, though benefits are generally short-term and vary by individual. Safety considerations are crucial; while most are well-tolerated, poses a significant risk of due to spores and is contraindicated for children under one year. Potential interactions with medications or allergies should be monitored, particularly for and in those with gastrointestinal sensitivities. These traditional remedies are commonly used for symptomatic relief in acute viral coughs but are not substitutes for medical care; individuals should consult a healthcare provider if cough persists beyond two weeks, is accompanied by blood in sputum, or involves breathing difficulties.

Cultural Practices

Steam inhalation has been a longstanding practice in European folk medicine to alleviate respiratory congestion associated with coughs. Inhaling warm steam is recommended to clear airways and provide symptomatic relief during colds that often involve coughing. This method involves breathing in steam from hot water, sometimes enhanced with saline, to moisten and soothe irritated mucous membranes. In Traditional Chinese Medicine (TCM), cupping and moxibustion are employed as non-herbal techniques to promote airway clearance and reduce cough symptoms. Cupping therapy, which creates suction on the skin using glass cups, is applied to back points to improve lung function and expel pathogens causing respiratory issues, as evidenced in treatments for severe coughs following infections. Moxibustion, involving the burning of mugwort near acupoints, warms the lungs and resolves phlegm to stop chronic coughs, particularly in children, by enhancing qi flow and reducing inflammation. These practices are often used together to address underlying imbalances leading to persistent coughing. Dietary approaches in various cultures emphasize warm soups to soothe the and ease cough irritation. In Jewish traditions, , known as "Jewish penicillin," is a folk remedy that provides warmth and hydration to relieve cold symptoms, including coughs, through its steaming vapors and nutrient-rich broth. Similarly, in Asian traditions, particularly Chinese, warming soups like those with ginger and chicken are consumed to moisturize the lungs, soothe from excessive coughing, and promote recovery from respiratory illnesses. Certain rituals in indigenous practices involve avoiding cold foods and drinks during respiratory illnesses to prevent exacerbating symptoms. Among Tarascan indigenous communities in , consuming "cold" foods is believed to cause or worsen gripa (colds with cough), leading to rituals that favor "hot" foods for balance and healing. In Filipino indigenous health beliefs, cold drinks and cooling foods are strictly avoided during illness to maintain and support recovery from conditions like coughs. These cultural practices are increasingly integrated into modern complementary therapies for cough management, with high acceptability reported in recent studies. Such integrations highlight their role in holistic approaches, often alongside brief supports for enhanced symptom relief.

Cough in Other Animals

Veterinary Perspectives

In , cough in domestic animals, particularly dogs and cats, is a common clinical sign indicating irritation or of the , often requiring prompt evaluation to identify underlying causes such as infectious or parasitic diseases. Among dogs, , also known as canine infectious respiratory disease complex (CIRDC), is a prevalent condition primarily caused by in combination with viral pathogens like canine parainfluenza virus, leading to . Recent outbreaks of atypical CIRDC (aCIRDC) have been reported in the United States and other regions from 2023 to 2025, characterized by severe in some cases unresponsive to standard antibiotics; investigations as of 2025 have not identified novel pathogens, but incidence remains elevated in certain areas. Heartworm disease, caused by , is another significant cause in dogs, where adult worms in the pulmonary arteries provoke chronic respiratory and coughing. In cats, cough is less frequent but often stems from lower , such as feline or , with occasionally implicated in upper respiratory infections. Clinical symptoms vary by species and etiology; in dogs with kennel cough, a characteristic dry, honking cough is typical, often triggered by excitement or pressure on the trachea, while heartworm-associated cough is softer, persistent, and worsens with exercise. Cats may exhibit wheezing or a softer, hacking cough, particularly in cases of bronchitis or parasitic migration, accompanied by open-mouth breathing or lethargy if severe. These signs resemble the human cough reflex in serving as a protective mechanism to clear airways, though veterinary assessment focuses on species-specific patterns. Diagnosis begins with , including thoracic to detect abnormal sounds like or wheezes, which can localize the issue to upper or lower airways. Thoracic radiographs are essential for visualizing pulmonary infiltrates, heart enlargement in heartworm cases, or bronchial patterns in inflammatory disease, often followed by fecal or serologic tests for parasites. , including , allows direct visualization of tracheal collapse or foreign bodies, particularly useful in chronic cases unresponsive to initial therapy. Treatment strategies prioritize supportive care, such as rest, humidified air, and cough suppressants like to reduce irritation, while addressing the underlying cause. Antibiotics, such as , are indicated for confirmed bacterial infections like , typically administered for 7-14 days, but are avoided in viral-predominant cases to prevent resistance. For heartworm, adulticide therapy with melarsomine is standard, combined with agents to manage coughing during treatment. In cats, bronchodilators like albuterol may be used for wheezing, with antibiotics reserved for secondary infections. Cough prevalence is notably high in animal shelters, where outbreaks of CIRDC can affect a substantial portion of dogs, with studies reporting up to 48% of dogs carrying pathogens that contribute to spread. Breed predispositions exacerbate risks; brachycephalic dogs, such as Bulldogs and Pugs, experience more frequent coughing from conformational airway obstruction, increasing susceptibility to infections. Zoonotic concerns arise with certain pathogens, as dogs and cats can transmit (H5N1) to humans through close contact, particularly in households with exposure to infected birds.

Comparative Physiology

In mammals, the is mediated by a conserved vagal afferent pathway, where sensory neurons detect irritants in the airways and trigger explosive expulsion through the to clear secretions and foreign particles. This mechanism varies in glottis control across ; for instance, with recurrent airway obstruction often exhibit frequent coughing to clear mucus-laden airways. Birds possess a unique unidirectional featuring that connect to the s, altering the dynamics of air expulsion compared to mammalian tidal . This structure facilitates rapid clearance of dust and particulates from the , often through sneeze-like behaviors rather than a traditional cough, as the enable efficient unidirectional airflow to minimize re-inhalation of irritants. In reptiles and amphibians, coughing is less frequent and less developed, with many species relying on buccopharyngeal pumping—a force-pump mechanism using the and muscles—for ventilation and limited irritant expulsion, rather than a dedicated . This pumping action, inherited from early vertebrates, supports intermittent air but lacks the diaphragmatic support for explosive coughs seen in mammals. Evolutionarily, the cough reflex serves a conserved role in airway protection across vertebrates, expelling pathogens, allergens, and aspirate to prevent aspiration, though its intensity and form adapt to environmental pressures; in cetaceans like whales, underwater living has led to specialized anatomical adaptations such as valved blowholes and separate nasal and oral pathways, reducing reliance on coughing by minimizing water entry during surfacing breaths. Recent evolutionary studies on P2X receptor homologs in highlight conserved ATP-sensing mechanisms in sensory neurons, providing insights into the origins of responses that parallel cough in higher vertebrates. A key difference lies in cough control, where humans uniquely possess the ability to initiate voluntary coughs alongside involuntary reflexes, mediated by higher cortical integration of vagal signals, whereas most animals exhibit only involuntary responses triggered by peripheral stimuli.

References

  1. https://www.ncbi.nlm.nih.gov/books/NBK493221/
  2. https://www.mayoclinic.org/symptoms/cough/basics/definition/sym-20050846
  3. https://www.mayoclinic.org/diseases-conditions/chronic-cough/symptoms-causes/syc-20351575
  4. https://my.clevelandclinic.org/health/symptoms/17755-cough
  5. https://www.lung.org/lung-health-diseases/warning-signs-of-lung-disease/cough/learn-about-cough
  6. https://www.mayoclinic.org/symptoms/cough/basics/causes/sym-20050846
  7. https://www.nhlbi.nih.gov/health/lung/bronchitis
  8. https://www.healthline.com/health/cold-flu/sputum-color
  9. https://my.clevelandclinic.org/health/symptoms/24636-coughing-up-phlegm
  10. https://www.aafp.org/pubs/afp/issues/1998/1201/p2015.html
  11. https://journal.chestnet.org/article/S0012-3692%2815%2952825-0/fulltext
  12. https://www.ncbi.nlm.nih.gov/books/NBK430791/
  13. https://www.aafp.org/pubs/afp/issues/2011/1015/p887.html
  14. https://journal.chestnet.org/article/S0012-3692%2817%2932918-5/fulltext
  15. https://www.mayoclinic.org/diseases-conditions/bronchitis/symptoms-causes/syc-20355566
  16. https://pmc.ncbi.nlm.nih.gov/articles/PMC9136724/
  17. https://doi.org/10.1016/j.rmed.2015.03.011
  18. https://journal.chestnet.org/article/S0012-3692(15)52831-6/fulltext
  19. https://pmc.ncbi.nlm.nih.gov/articles/PMC8640838/
  20. https://pmc.ncbi.nlm.nih.gov/articles/PMC6502102/
  21. https://teachmephysiology.com/respiratory-system/regulation/cough-reflex/
  22. https://pmc.ncbi.nlm.nih.gov/articles/PMC3415124/
  23. https://pubs.aip.org/aip/pof/article/32/12/125102/1063151/The-motion-of-respiratory-droplets-produced-by
  24. https://www.meddean.luc.edu/lumen/meded/elective/pulmonary/cough/cough.htm
  25. https://pmc.ncbi.nlm.nih.gov/articles/PMC4470868/
  26. https://link.springer.com/article/10.1007/s11302-022-09877-z
  27. https://pmc.ncbi.nlm.nih.gov/articles/PMC7578480/
  28. https://publications.ersnet.org/content/erj/49/2/1700082
  29. https://pubs.aip.org/aip/pof/article/34/4/041911/2844319/Influence-of-cough-airflow-characteristics-on
  30. https://blogs.the-hospitalist.org/content/post-covid-cough-linked-neurological-dysfunction
  31. https://pmc.ncbi.nlm.nih.gov/articles/PMC8138462/
  32. https://www.sciencedirect.com/science/article/abs/pii/S1569904823000277
  33. https://link.springer.com/article/10.1007/s00408-025-00812-8
  34. https://www.sciencedirect.com/science/article/abs/pii/S1471489215000314
  35. https://www.ncbi.nlm.nih.gov/books/NBK8142/
  36. https://www.merckmanuals.com/professional/infectious-diseases/respiratory-viruses/overview-of-viral-respiratory-infections
  37. https://wwwnc.cdc.gov/eid/article/31/6/24-1097_article
  38. https://pmc.ncbi.nlm.nih.gov/articles/PMC12398010/
  39. https://pmc.ncbi.nlm.nih.gov/articles/PMC7044178/
  40. https://pmc.ncbi.nlm.nih.gov/articles/PMC7665094/
  41. https://pmc.ncbi.nlm.nih.gov/articles/PMC8583367/
  42. https://pmc.ncbi.nlm.nih.gov/articles/PMC6733730/
  43. https://pmc.ncbi.nlm.nih.gov/articles/PMC6026423/
  44. https://pmc.ncbi.nlm.nih.gov/articles/PMC8526874/
  45. https://www.ncbi.nlm.nih.gov/books/NBK482437/
  46. https://pmc.ncbi.nlm.nih.gov/articles/PMC7094692/
  47. https://pmc.ncbi.nlm.nih.gov/articles/PMC6031196/
  48. https://pmc.ncbi.nlm.nih.gov/articles/PMC3598823/
  49. https://pubmed.ncbi.nlm.nih.gov/23962764/
  50. https://pmc.ncbi.nlm.nih.gov/articles/PMC5708401/
  51. https://pmc.ncbi.nlm.nih.gov/articles/PMC7941673/
  52. https://pmc.ncbi.nlm.nih.gov/articles/PMC7097707/
  53. https://www.aafp.org/pubs/afp/issues/2017/1101/p575.html
  54. https://journal.chestnet.org/article/S0012-3692(15)52825-0/fulltext
  55. https://www.mayoclinic.org/diseases-conditions/pet-allergy/symptoms-causes/syc-20352192
  56. https://health.clevelandclinic.org/can-best-combat-effects-dry-winter-air
  57. https://erj.ersjournals.com/content/55/1/1901136
  58. https://www.mayoclinic.org/symptoms/cough/basics/when-to-see-doctor/sym-20050846
  59. https://journal.chestnet.org/article/S0012-3692(15)52858-4/fulltext
  60. https://www.seattlechildrens.org/conditions/a-z/cough/
  61. https://pmc.ncbi.nlm.nih.gov/articles/PMC11903822/
  62. https://jtd.amegroups.org/article/view/25427/html
  63. https://www.atsjournals.org/doi/10.1164/rccm.201908-1590ST
  64. https://www.ncbi.nlm.nih.gov/books/NBK563195/
  65. https://www.aafp.org/pubs/afp/issues/2017/1101/p611.html
  66. https://pmc.ncbi.nlm.nih.gov/articles/PMC8754510/
  67. https://publications.ersnet.org/content/erjor/11/1/00571-2024
  68. https://aacijournal.biomedcentral.com/articles/10.1186/s13223-024-00923-6
  69. https://pmc.ncbi.nlm.nih.gov/articles/PMC3555364/
  70. https://www.sciencedirect.com/science/article/pii/S0954611123000306
  71. https://publications.ersnet.org/content/erjor/10/6/00529-2024
  72. https://allergyrespiratory.com/wp-content/uploads/2025/04/NEJMra2309906-chronic-cough-march-2025.pdf
  73. https://pmc.ncbi.nlm.nih.gov/articles/PMC7123091/
  74. https://www.ncbi.nlm.nih.gov/books/NBK359/
  75. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-nasal-mucus-color-what-does-it-mean/
  76. https://my.clevelandclinic.org/health/body/mucus
  77. https://pmc.ncbi.nlm.nih.gov/articles/PMC3410464/
  78. https://pmc.ncbi.nlm.nih.gov/articles/PMC8666560/
  79. https://pmc.ncbi.nlm.nih.gov/articles/PMC11745195/
  80. https://pmc.ncbi.nlm.nih.gov/articles/PMC9244241/
  81. https://pmc.ncbi.nlm.nih.gov/articles/PMC7100269/
  82. https://pmc.ncbi.nlm.nih.gov/articles/PMC9487209/
  83. https://www.cdc.gov/antibiotic-use/media/pdfs/Common-Cold-P.pdf
  84. https://medlineplus.gov/ency/article/002104.htm
  85. https://health.clevelandclinic.org/mucus-and-phlegm-what-to-do-if-you-have-too-much
  86. https://pubmed.ncbi.nlm.nih.gov/37355498/
  87. https://www.mayoclinic.org/diseases-conditions/chronic-cough/diagnosis-treatment/drc-20351580
  88. https://health.clevelandclinic.org/sore-throat-remedies-that-actually-work
  89. https://www.lung.org/lung-health-diseases/lung-disease-lookup/bronchitis/treating-managing
  90. https://www.lung.org/lung-health-diseases/warning-signs-of-lung-disease/cough/diagnosing-treating
  91. https://www.aafp.org/pubs/afp/issues/2007/0215/p476.html
  92. https://www.cdc.gov/acute-bronchitis/about/index.html
  93. https://pmc.ncbi.nlm.nih.gov/articles/PMC6942543/
  94. https://pmc.ncbi.nlm.nih.gov/articles/PMC6649889/
  95. https://pmc.ncbi.nlm.nih.gov/articles/PMC5831652/
  96. https://journals.sagepub.com/doi/abs/10.1177/0194599812471817
  97. https://www.tandfonline.com/doi/full/10.1080/14656566.2018.1462795
  98. https://www.ncbi.nlm.nih.gov/books/NBK546786/
  99. https://www.liebertpub.com/doi/10.4187/respcare.04165
  100. https://pmc.ncbi.nlm.nih.gov/articles/PMC10658629/
  101. https://pmc.ncbi.nlm.nih.gov/articles/PMC10333155/
  102. https://journal.chestnet.org/article/S0012-3692%2815%2948692-1/abstract
  103. https://publications.ersnet.org/content/breathe/19/4/230165
  104. https://www.merck.com/news/merck-receives-positive-european-union-chmp-opinion-for-gefapixant/
  105. https://www.delveinsight.com/blog/mercks-gefapixant-for-chronic-refractory-cough
  106. https://dtb.bmj.com/content/63/2/22
  107. https://www.atsjournals.org/doi/10.1164/rccm.202503-0636ED
  108. https://www.healio.com/news/pulmonology/20250401/camlipixant-safe-yields-improvements-in-refractory-chronic-cough
  109. https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.2003
  110. https://www.atsjournals.org/doi/10.1164/rccm.201704-0769OC
  111. https://pubs.asha.org/doi/10.1044/2025_AJSLP-25-00124
  112. https://www.pharmacytimes.com/view/chest-2025-improving-access-to-chronic-cough-treatment-through-a-digital-therapeutic-solution
  113. https://pmc.ncbi.nlm.nih.gov/articles/PMC11374482/
  114. https://journals.lww.com/md-journal/fulltext/2025/10100/chronic_cough__a_review_and_prospects.68.aspx
  115. https://pmc.ncbi.nlm.nih.gov/articles/PMC12461901/
  116. https://www.researchgate.net/publication/374100774_Inhalation_delivery_of_nucleic_acid_gene_therapies_in_preclinical_drug_development
  117. https://www.chestnet.org/guidelines-and-topic-collections
  118. https://pmc.ncbi.nlm.nih.gov/articles/PMC4047603/
  119. https://bmcprimcare.biomedcentral.com/articles/10.1186/s12875-021-01501-0
  120. https://publications.ersnet.org/content/erj/45/5/1479
  121. https://publications.ersnet.org/content/erj/44/5/1149
  122. https://bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-024-03095-6
  123. https://www.tandfonline.com/doi/full/10.2147/COPD.S133148
  124. https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-17495-6
  125. https://pmc.ncbi.nlm.nih.gov/articles/PMC1277009/
  126. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0078081
  127. https://www.tandfonline.com/doi/full/10.1080/03007995.2022.2065142
  128. https://pmc.ncbi.nlm.nih.gov/articles/PMC10619292/
  129. https://jamanetwork.com/journals/jama/fullarticle/2805540
  130. https://journals.asm.org/doi/10.1128/cmr.00131-24
  131. https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-025-11468-3
  132. https://www.nature.com/articles/d41586-025-03412-x
  133. https://www.nature.com/articles/s41598-024-54397-y
  134. https://www.sciencedirect.com/science/article/abs/pii/S2212534524000133
  135. https://www.cidrap.umn.edu/covid-19/vaccination-may-reduce-elevated-risk-airway-diseases-covid-survivors
  136. https://www.sciencedirect.com/science/article/pii/S0163445324002937
  137. https://www.ancient-origins.net/artifacts-ancient-writings/ebers-papyrus-0012333
  138. https://journals.lww.com/hrtv/fulltext/2002/03040/history_of_medicine.10.aspx
  139. https://the-past.com/feature/magical-honey-some-unusual-uses-in-ancient-egypt/
  140. https://pubmed.ncbi.nlm.nih.gov/17063641/
  141. https://www.tandfonline.com/doi/full/10.1080/03007995.2021.1960493
  142. https://pmc.ncbi.nlm.nih.gov/articles/PMC4264806/
  143. https://www.mayoclinic.org/symptoms/cough/expert-answers/honey/faq-20058031
  144. https://www.healthychildren.org/English/health-issues/conditions/chest-lungs/Pages/Coughs-and-Colds-Medicines-or-Home-Remedies.aspx
  145. https://www.lungeninformationsdienst.de/aktuelles/schwerpunktthemen/husten
  146. https://www.ndr.de/ratgeber/gesundheit/Hausmittel-gegen-Husten-Was-hilft-wirklich,hustenmittel104.html
  147. https://www.mayoclinic.org/diseases-conditions/common-cold/in-depth/cold-remedies/art-20046403
  148. https://pmc.ncbi.nlm.nih.gov/articles/PMC7456299/
  149. https://pmc.ncbi.nlm.nih.gov/articles/PMC10278442/
  150. https://www.ncbi.nlm.nih.gov/books/NBK92752/
  151. https://www.researchgate.net/publication/292162183_Herbal_Medicine_for_Cough_A_Systematic_Review_and_Meta-Analysis
  152. https://www.cdc.gov/botulism/prevention/index.html
  153. https://pmc.ncbi.nlm.nih.gov/articles/PMC3448763/
  154. https://vcahospitals.com/know-your-pet/coughing-in-cats
  155. https://www.avma.org/resources-tools/pet-owners/petcare/canine-infectious-respiratory-disease-complex-kennel-cough
  156. https://www.avma.org/news/questions-remain-canine-respiratory-disease-cases-fall
  157. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1617147/full
  158. https://www.heartwormsociety.org/heartworms-in-dogs
  159. https://www.vetfolio.com/learn/article/bordetella-infections-in-dogs-and-cats-pathogenesis-clinical-signs-and-diagnosis
  160. https://metrovetclinic.com/resources/kennel-cough-vs-heartworm-cough/
  161. https://www.petmd.com/cat/symptom/cat-coughing
  162. https://pmc.ncbi.nlm.nih.gov/articles/PMC6985277/
  163. https://todaysveterinarypractice.com/respiratory-medicine/evaluating-and-managing-chronic-cough-in-dogs/
  164. https://www.vin.com/apputil/content/defaultadv1.aspx?pId=11290&id=4252571
  165. https://www.petmd.com/dog/conditions/respiratory/kennel-cough-dogs-what-are-symptoms-and-how-kennel-cough-treated
  166. https://www.merckvetmanual.com/respiratory-system/respiratory-diseases-of-small-animals/kennel-cough
  167. https://www.avma.org/resources-tools/pet-owners/petcare/heartworm-disease
  168. https://pmc.ncbi.nlm.nih.gov/articles/PMC7166506/
  169. https://vcahospitals.com/know-your-pet/brachycephalic-airway-syndrome-in-dogs
  170. https://www.avma.org/resources-tools/animal-health-and-welfare/animal-health/avian-influenza
  171. https://pmc.ncbi.nlm.nih.gov/articles/PMC2600237/
  172. https://pmc.ncbi.nlm.nih.gov/articles/PMC2882536/
  173. https://pubmed.ncbi.nlm.nih.gov/12755293/
  174. https://pmc.ncbi.nlm.nih.gov/articles/PMC5138057/
  175. https://www.britannica.com/science/respiratory-system/Amphibians
  176. https://www.vin.com/apputil/content/defaultadv1.aspx?pId=11257&catId=32383&id=3863270
  177. https://pubmed.ncbi.nlm.nih.gov/17516445/
  178. https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0427
  179. https://pmc.ncbi.nlm.nih.gov/articles/PMC3234184/
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