Is carpal tunnel syndrome caused by nerve pressure?

Pressure on the median nerve inside the carpal tunnel of the wrist can produce symptoms of carpal tunnel syndrome (CTS). In fact, any condition that causes abnormal pressure in the tunnel can produce symptoms of CTS. Various types of arthritis can cause swelling and pressure in the carpal tunnel. Other conditions in the body can produce symptoms of CTS. Pregnancy can cause fluid to be retained, leading to extra pressure in the carpal tunnel. Diabetics may report symptoms of CTS, which may be from a problem in the nerve (called neuropathy), or from actual pressure on the median nerve. Also, fractured wrist bones may later cause CTS if the healed fragments result in abnormal pressure and irritation on the flexor tendons.