The carpal tunnel is a narrow passageway in the wrist made up of ligaments and bones. The median nerve and the tendons that connect the fingers to the muscles of the forearm pass through this tightly spaced tunnel.
Carpal tunnel syndrome, also known as median nerve entrapment, occurs when swelling or irritation of the tendons in the carpal tunnel results in pressure on the median nerve causing pain in the palm side of the wrist and pain and tingling in the fingers. The median nerve controls sensations to the palm side of the thumb and fingers, as well as impulses to some small muscles in the hand that allow the fingers and thumb to move.
Symptoms usually start gradually, with frequent burning, tingling, or numbness in the palm of the hand and the fingers, especially the index, middle and ring fingers. Pain can sometimes travel up the arm and affect the shoulder. The symptoms often first appear during the night. As symptoms worsen, people might feel pain, weakness, or numbness in the hand and wrist, radiating up the arm during the day. Decreased grip strength may make it difficult to form a fist, grasp small objects, or perform other manual tasks. If not properly treated, CTS can cause irreversible nerve damage and permanent deterioration of muscle tissue.