Carpal tunnel syndrome is numbness, tingling, and pain in the fingers and hand due to pressure on the median nerve in the wrist. The median nerve passes down the forearm to the hand, where it controls muscles at the base of the thumb and sensation in the thumb half of the palm. En route to the hand, the nerve passes through the carpal tunnel, a space between the wrist bones and the ligament that lies over them; in addition to the nerve, tendons pass through the space.
Carpal tunnel syndrome occurs when the nerve is compressed, which may be due to swelling of the tendons or a build-up of fluid in the carpal tunnel as a result of overuse, arthritis, diabetes, or thyroid problems.
It can also occur with hormonal changes during pregnancy or around menopause. The pressure on the nerve results in numbness, tingling, pain, and loss of grip in the thumb, first two fingers, and half of the ring (third) finger. Carpal tunnel syndrome is usually treated with rest, splinting, or medication. Sometimes, surgery is needed.