Carpal tunnel syndrome is due to squeezing of the median nerve as it passes through the wrist to the hand. This nerve is contained in the carpal tunnel, a narrow channel just above the wrist. In carpal tunnel syndrome, the channel starts to shrink, compressing the nerve and causing inflammation. The result is hand pain, numbness, tingling, and sometimes, hand weakness or restricted movement. The little finger is not affected.
Carpal tunnel syndrome is one of the most common causes of claims for workers' injury compensation, second only to lower back pain. Women are at three times greater risk of developing carpal tunnel syndrome compared to men. It occurs at any age, but is more common in people over 50 years old.