Emergency nursing is a specialty within the field of professional nursing focusing on the care of patients who require prompt medical attention to avoid long-term disability or death. In addition to addressing "true emergencies," emergency nurses increasingly care for people who are unwilling or unable to get primary medical care elsewhere and come to emergency departments for help. In fact, only a small percentage of emergency department (ED) patients have emergency conditions such as a stroke, heart attack or major trauma. Emergency nurses also tend to patients with acute alcohol and/or drug intoxication, psychiatric and behavioral problems and those who have been raped.

Emergency nurses are most frequently employed in hospital emergency departments, although they may also work in urgent care centers, sports arenas, and on medical transport aircraft and ground ambulances.

Around the 1800s hospitals became more popular and there was a growth in emergency care. The first development of an emergency room was originally called the "First Aid Room." Originally, nurses only dressed wounds, applied eye ointments, treated minor burns with salves and bandages, and attended patients with minor illnesses like colds and sore throats. The rule of thumb was first in, first served, but there were many cases where some people were in more need of emergency care than others, and as the situation became more intolerable, one of the greatest medical developments came into perspective: triage.

For centuries triage had been used in war but was not yet established in the emergency department. The first time triage was referred to during a non-disaster situation was at Yale New Haven Hospital, Connecticut, United States in 1963, and since then has become developed and more defined.

Emergency nurses must be able to sit, stand, walk, reach, squat and lift throughout their eight- or twelve-hour shift. They must have good manual dexterity, hearing and vision. They must understand principles of human development, anatomy, physiology, pharmacology, They must also have a working knowledge of the many legal issues impacting health care such as consent, handling of evidence, mandatory reporting of child and elder abuse, and involuntary psychiatric holds. They must be adept and comfortable working with patients of many different backgrounds, cultures, religions, ages and types of disabilities. They must be calm and professional at all times, especially when dealing with situations which are difficult, emotional or disgusting. Emergency nurses must also know how to care for themselves physically and emotionally.

The role of the emergency nurse is to evaluate and monitor patients and to manage their care in the emergency department. They may also supervise licensed practical nurses and unlicensed assistive personnel ("nurse aides" or "care partners"). It can be a challenge to get everything done quickly and correctly in an ever-changing environment. Some ED nurse functions are common to other nursing specialties, while others are specific to emergency nursing. These can be divided into 1.) assessment, 2.) planning and managing care, 3.) tasks, 4.) communication, and 5.) teaching.

An emergency nurse is assigned to triage patients as they arrive in the emergency department, and as such, is the first professional patients will see. Therefore, this emergency nurse must be skilled at rapid, accurate physical examination and early recognition of life-threatening conditions. Based on the triage nurse's findings, a triage category is assigned. The Emergency Severity Index (ESI) triages patients into five groups from 1 (most urgent) to 5 (least urgent).

An experienced emergency nurse is put in the role of charge nurse or team leader. This nurse is responsible for the overall "flow" of the department. He or she assigns nurses to patients, assures patients are being transported to and from tests outside the ED, addresses patient complaints and concerns, communicates with the house supervisor, takes phone calls, and assures nurses get their breaks.