Carpal tunnel syndrome (CTS) is pain that occurs in the hand and wrist when a nerve that runs through the forearm to the hand called the median nerve is pinched or compressed at the wrist. The “carpal tunnel” is a passageway in the wrist that allows the median nerve and several tendons of muscles that move the thumb and fingers to pass from the forearm into the hand. The tunnel itself is formed by the bones of the wrist (called carpals) on one side and a broad stiff ligament on the other (i.e. palm) side of the wrist. When the tendons that pass through the tunnel become inflamed or swell, this puts pressure on the median nerve and causes the symptoms of CTS: numbness, pain, and weakness in the hand and wrist.

Treatments for CTS are available that can help relieve the pain and numbness and restore normal function of the wrists and hands in most cases. The majority of people recover completely and do not suffer recurrences of the disorder.

CTS tends to affect mainly middle aged people, and is more common in women than men. It may affect up to 10 percent of the entire population.