CausesBy Mayo Clinic staff
A pinched nerve occurs when too much pressure (compression) is applied to a nerve by surrounding tissues. In some cases, this tissue might be bone or cartilage — such as in the case of a herniated spinal disk that compresses a nerve root. In other cases, muscle or tendons may be the culprits. In the case of carpal tunnel syndrome, a variety of tissues may be responsible for compression of the carpal tunnel's median nerve, including swollen tendon sheaths within the tunnel, enlarged bone that narrows the tunnel, or a thickened and degenerated ligament.
A number of conditions may cause tissue to compress a nerve or nerves. Injury, poor posture, osteoarthritis, stress from repetitive job, hobby or sports activities, and obesity are common contributors to or causes of nerve pressure.
This pressure causes inflammation of the nerve and disrupts the nerve's function. If a nerve is pinched for only a short time, there's typically no permanent damage. Once the pressure is relieved, nerve function returns to normal. However, if the pressure continues, chronic pain and permanent nerve damage can occur.
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