Radiculopathy (from Latin radix 'root'; from Ancient Greek πάθος (pathos) 'suffering'), also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly (a neuropathy). Radiculopathy can result in pain (radicular pain), weakness, altered sensation (paresthesia) or difficulty controlling specific muscles. Pinched nerves arise when surrounding bone or tissue, such as cartilage, muscles or tendons, put pressure on the nerve and disrupt its function.

In a radiculopathy, the problem occurs at or near the root of the nerve, shortly after its exit from the spinal cord. However, the pain or other symptoms often radiate to the part of the body served by that nerve. For example, a nerve root impingement in the neck can produce pain and weakness in the forearm. Likewise, an impingement in the lower back or lumbar-sacral spine can be manifested with symptoms in the foot.

The radicular pain that results from a radiculopathy should not be confused with referred pain, which is different both in mechanism and clinical features. Polyradiculopathy refers to the condition where more than one spinal nerve root is affected.

Radiculopathy most often is caused by mechanical compression of a nerve root usually at the exit foramen or lateral recess. It may be secondary to intervertebral disk herniation (most commonly at C7 and then the C6 level), degenerative disc disease, osteoarthritis, facet joint degeneration/hypertrophy, ligamentous hypertrophy, spondylolisthesis, or a combination of these factors. Other possible causes of radiculopathy include neoplastic disease, infections such as shingles, HIV, or Lyme disease, spinal epidural abscess, spinal epidural hematoma, proximal diabetic neuropathy, Tarlov cysts, or, more rarely, sarcoidosis, arachnoiditis, tethered spinal cord syndrome, or transverse myelitis.^{[verification needed]}

Repeated, longer term exposure (5 years or more) to certain work-related activities may put people at risk of developing lumbosacral radiculopathy. These behaviours may include physically demanding work, bending over or twisting at the trunk, lifting and carrying, or a combination of these activities.

Less common causes of radiculopathy include injury caused by tumor (which can compress nerve roots locally) and diabetes (which can effectively cause ischemia or lack of blood flow to nerves).^{[medical citation needed]}

Signs and Symptoms

Radiculopathy is a diagnosis commonly made by physicians in primary care specialties, orthopedics, physiatry, and neurology. The diagnosis may be suggested by symptoms of pain, numbness, paresthesia, and weakness in a pattern consistent with the distribution of a particular nerve root, such as sciatica. Neck pain or back pain may also be present.^{[medical citation needed]} Physical examination may reveal motor and sensory deficits in the distribution of a nerve root. In the case of cervical radiculopathy [fr], Spurling's test may elicit or reproduce symptoms radiating down the arm. Similarly, in the case of lumbosacral radiculopathy, a straight leg raise maneuver or a femoral nerve stretch test may demonstrate radiculopathic symptoms down the leg. Deep tendon reflexes (also known as a stretch reflex) may be diminished or absent in areas innervated by a particular nerve root.^{[citation needed]}