A pinched nerve is a nerve that has pressure applied to it at some point, preventing nutrients and signals reaching it as they should. It is similar in some ways to the way in which a water hose can become kinked, cutting off the water supply. From the point onward of the pinch, the nerve fails to get the nutrients it needs to continue functioning properly. This prevents the nerve from send signals to back to the brain, resulting in numbness. Moreover, continued pinching can cause the nerve to permanently die, since it cannot exist long without nutrients.
Compression along any of the many nerves that leave the brain can cause them to become pinched. Nerves in the brain and the spinal cord are called central. Those that leave the spinal cord and brain in long, thin fibers are called peripheral. Compression and pinching can occur in either type of nerve.
Peripheral nerves can become pinched if a person suffers spinal injury, like a herniated disc. This compresses the spine, and may in turn pinch one or more nerves. Another common area to get pinched nerve is the wrist. Carpal tunnel syndrome is often the result of improper positioning of the hands that actually pinches off nerves and causes a loss of sensation, as the tissues around the nerve swell.
Usually, a person with a pinched nerve notices a loss in sensation in the affected area as well as pain. It is generally not the compressed nerve that causes the pain, but the condition causing the problem in the first place. As tissues around the nerve swell, or as a back injury becomes more pronounced, as in a herniated disc, pain can be significant.
The person with the pinched nerve may not feel the loss of sensation at the nerve site. So, for example, a nerve in the back that is pinched might cause a loss of sensation in the arms, legs, hands, or feet. While the back aches from bone spurs or spinal compression, the individual may also note numbness in one or more of these areas, indicating that there is a nerve problem.
Treatment depends on the area where the nerve is pinched. If a slipped disc is clearly causing the problem, many patients choose spinal surgery to repair or remove the disc. In carpal tunnel injuries, reducing the motion required by the affected wrist may help restore sensation. Sometimes, using ergonomically designed equipment, like vertical keyboards can help reduce pressure on a nerve.
Swelling around an injury may be treated with cortisone injections or with anti-inflammatory medications. Sometimes, a person with a pinched nerve may require physical therapy to help restore function. How much function is restored often depends upon how long the nerve has been pinched. If the condition has existed for years, numbness may persist after repair attempts because the nerve no longer works past its pinched point. Early treatment frequently offers a better chance at restoring full function.