The palm surface where the wrist and hand connect together contains the ‘carpal tunnel’. Usually nine tendons and one nerve go through this tunnel-like area. It is bordered by the wrist bones on the bottom and a strap-like ligament on top.
If these tendons swell up around the nerve, it can pinch the nerve and cause carpal tunnel syndrome. Injuries, tumors or some unusual diseases cause buildup of other fluid or tissue in the area and also cause carpal tunnel syndrome.
The pain may be felt in the palm, and extend into the thumb, index,middle and ring fingers. It may feel like an ache, burning, numbness or tingling. Holding the wrist in a flexed down position may increase the pain. Carpal tunnel syndrome often is painful at night or driving a car. Pain may also go from the wrist up the forearm.
Any condition which puts unusual pressure on the nerve in the carpal tunnel may cause carpal tunnel syndrome. Usually this is due to swelling in the tendons, or swollen arthritic tissue in the area. Excessive or unusual use of the fingers may cause tendinitis and swelling resulting in compression of the nerve. Inflammation and swelling from arthritic diseases such as rheumatoid arthritis also will pinch or crowd the nerve. Sometimes conditions causing fluid to build up in the carpal tunnel such as injuries or pregnancy will compress the nerve.
If pain runs up the palm side of the hand into all of the fingers except the little finger, especially at night or when using the hand in certain positions, there is a good chance that carpal tunnel syndrome is present. Tapping on the middle of the undersurface of the wrist may cause pain to shoot into the fingers or forearm. Specialized nerve conduction velocity testing (NCV) may confirm the diagnosis. At the same time, electromyography (EMG) testing will determine if the muscles of the hand have been affected.
Treatment depends upon the cause and severity of the symptoms. If the hand is weak as well as painful, surgery may be considered. If left untreated, permanent weakness may result. Before that point, physical therapy and a change in activities or work conditions are important. Often a brace to keep the wrist straight, especially at night is recommended. Sometimes injections of a cortisone-like medication are used to reduce inflammation and swelling. If rheumatoid arthritis is causing carpal tunnel syndrome, specific treatment prescribed by a rheumatologist will reduce swelling in the wrist area and reduce the pain.