Carpal tunnel syndrome is a hand and arm condition that causes numbness, tingling and other symptoms. Carpal tunnel syndrome is caused by a pinched nerve in your wrist. A number of factors can contribute to carpal tunnel syndrome, including the anatomy of your wrist, certain underlying health problems and possibly patterns of hand use. Bound by bones and ligaments, the carpal tunnel is a narrow passageway located on the palm side of your wrist. This tunnel protects a main nerve to your hand and the nine tendons that bend your fingers. Compression of the nerve produces the numbness, tingling and, eventually, hand weakness that characterize carpal tunnel syndrome. Fortunately, for most people who develop carpal tunnel syndrome, proper treatment usually can relieve the tingling and numbness and restore wrist and hand function.