The carpal tunnel is a small narrow passageway located on the front of your wrist which is formed by the bones and ligaments. The median nerve, blood vessels and tendons of your hand pass through the carpal tunnel. Carpal tunnel syndrome is a condition that affects the median nerve as it passes through the tunnel. When the median nerve becomes compressed in the carpal tunnel, the symptoms may present as numbness, weakness and tingling in the hand or arm.

Compression of the median nerve will occur if there is swelling or thickening of the tendons in the carpal tunnel.