Causes

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 cause the condition.

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, including:

• Injury
• Rheumatoid or wrist arthritis
• Stress from repetitive work
• Hobbies or sports activities
• Obesity

If a nerve is pinched for only a short time, there's usually 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.