What Causes Carpal Tunnel Syndrome? Carpal tunnel syndrome is a localized peripheral neuropathy that affects the hands. At the base of the hand is a narrow place between bones and ligament where the median nerve and tendons are found. This area is called the carpal tunnel. When the median nerve, which runs from the forearm into the hand, becomes pressed, squeezed or inflamed at the wrist, the result may be numbness, pain and weakness in the hand and wrist, frequently reaching up along the arm. Symptoms of carpal tunnel syndrome (CTS) may increase gradually. Signs of CTS usually are first noticed at night. Common symptoms include burning, tingling or numbness in the palm of the hand and along the fingers, especially the thumb, index and middle finger. These feelings may intensify to the point where it becomes difficult to hold small obje...