It has been estimated that 1 out of 1000 of adults in the United States has carpal tunnel syndrome. It may occur for no apparent reason or it may be caused by fluid retention, pregnancy, injury or other medical problems. Jobs requiring repeated movement of the wrist, use of vibrating machinery, repeated squeezing or pinching of the hand, direct pressure on the wrist or those that require that the hand and wrist be held in an abnormal posture for prolonged periods make carpal tunnel syndrome more likely. Among medical problems that cause carpal tunnel syndrome, rheumatoid arthritis is the most common. Carpal tunnel syndrome may accompany mild or severe rheumatoid arthritis and may occur at any time during the disease.
Wrist swelling due to other types of arthritis also can cause carpal tunnel syndrome.
Since osteoarthritis typically does not cause wrist swelling, it is not a common cause of carpal tunnel syndrome. It should be emphasized that not all people with numbness and tingling in the fingers have carpal tunnel syndrome. Pinched nerves in the neck, vitamin deficiencies, diabetes, infections, multiple sclerosis, and toxin exposure all can cause similar symptoms. A rheumatologist suspects carpal tunnel syndrome when a patient reports pain, numbness and tingling traveling into the fingers or forearms. During physical examination, the physician may use a reflex hammer to tap the wrist in the area of the carpal tunnel.