Carpal tunnel syndrome is a common disorder that causes pain and interferes with the use of the hand. It is caused by pressure on the median nerve as the nerve passes through a canal formed by the bones and ligaments in the wrist. This canal is known as the carpal tunnel. A variety of conditions can cause the carpal tunnel to narrow and put pressure on the median nerve. These include injuries, such as wrist fractures; arthritis complicated by swelling of the tendons in the carpal tunnel; pregnancy, which may cause the synovium (membrane) around the tendons to thicken; and glandular abnormalities, such as diabetes and thyroid disorders. Repetitive wrist motions also may cause the disorder.
Symptoms of carpal tunnel syndrome include pain and numbness in the thumb and in the index, middle, and ring fingers. Many people are awakened at night with these symptoms. Some sufferers experience weakness of certain hand muscles and may drop objects. Symptoms often occur with the wrist in certain positions, such as while driving an automobile or while holding a book for reading.
Doctors treat carpal tunnel syndrome by attempting to improve the underlying condition. In many cases, doctors apply a splint to the wrist and prescribe anti-inflammatory medications. In some cases, surgery to enlarge the carpal tunnel is performed to relieve symptoms and to prevent permanent damage to the median nerve.
