Carpal tunnel release (Carpal tunnel syndrome - CTS) is a surgery used to treat and potentially heal the painful condition known as carpal tunnel syndrome. CTS is a medical condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel. The main symptoms are pain, numbness and tingling in the thumb, index finger, middle finger and the thumb side of the ring finger. Symptoms typically start gradually and during the night. Pain may extend up the arm. Weak grip strength may occur, and after a long period of time the muscles at the base of the thumb may waste away. In more than half of cases, both sides are affected. Carpal tunnel syndrome can also be caused by injury, such as a sprain or fracture, or repetitive use of a vibrating tool. It's also been linked to pregnancy, diabetes, thyroid disease, and rheumatoid arthritis