What is the primary cause of carpal tunnel syndrome?

The primary cause of carpal tunnel syndrome is the compression of the median nerve as it passes through the carpal tunnel, a narrow passageway in the wrist. This nerve is responsible for sensation in the thumb, index finger, middle finger, and half of the ring finger, as well as controlling some small muscles at the base of the thumb.

When the median nerve is compressed, it can lead to symptoms such as numbness, tingling, weakness, and pain in the hand and wrist. The compression can occur due to various factors including inflammation, anatomical variations, or increased pressure within the carpal tunnel.

While overuse of the wrist, inflammation of the wrist ligaments, and arthritic changes can contribute to the conditions that lead to carpal tunnel syndrome, they generally act as risk factors rather than the direct cause. The direct impact on the median nerve from compression is what specifically characterizes this syndrome. Understanding this mechanism helps to clarify how certain activities or conditions can exacerbate the problem but ultimately underscore that nerve compression is the key issue in carpal tunnel syndrome.