Carpal tunnel syndrome involves which nerve?

• A. Ulnar nerve
• B. Radial nerve
• C. Median nerve
• D. Axillary nerve

Answer: (C)

Carpal tunnel syndrome results from compression of the median nerve as it passes through the carpal tunnel at the wrist. This nerve supplies sensation to the thumb, index, middle, and the lateral half of the ring finger, and it controls key hand muscles near the base of the thumb. When compressed, symptoms include numbness, tingling, and sometimes weakness in those areas, which is characteristic of this condition. The other nerves listed don’t run through the carpal tunnel or don’t innervate the same hand regions: the ulnar nerve mainly serves the little finger and part of the ring finger and some intrinsic hand muscles; the radial nerve covers the back of the hand and some forearm muscles but doesn’t pass through the carpal tunnel; the axillary nerve supplies the shoulder region. Hence, the nerve involved in carpal tunnel syndrome is the median nerve.