What is carpal tunnel syndrome? Diseases, Disorders, and Other Health Problems Read more from Chapter Health and Medicine

Local pressure, such as crossing or sitting on your legs, may temporarily compress a nerve, removing sensory and motor function in your foot. When the local pressure is removed, the familiar feeling of “pins and needles” is felt as the nerve endings become reactivated.

Carpal tunnel syndrome occurs when a branch of the median nerve in the forearm is compressed at the wrist as it passes through the tunnel formed by the wrist bones (or carpals), and a ligament that lies just under the skin. The syndrome occurs most often in middle age and more so in women than men. The symptoms are intermittent at first, then become constant. Numbness and tingling begin in the thumb and first two fingers; then the hand and sometimes the whole arm becomes painful. Treatment involves wrist splinting, weight loss, and control of edema; treatments for arthritis may help also. If not, a surgical procedure in which the ligament at the wrist is cut can relieve pressure on the nerve. Those who work continuously with computer keyboards are particularly vulnerable to carpal tunnel syndrome. To minimize the risk of developing this problem, operators should keep their wrists straight as they type, rather than tilting the hands up. It is also best to place the keyboard at a lower position than a standard desktop.