Carpal tunnel syndrome involves which nerve?

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

Answer: (C)

Carpal tunnel syndrome is a compression neuropathy of the median nerve as it passes through the carpal tunnel at the wrist. When the median nerve is squeezed, you typically feel numbness, tingling, or pain in the thumb, index finger, middle finger, and the radial half of the ring finger, and you may notice weakness in the thumb’s movements due to affected thenar muscles. This pattern directly reflects the median nerve’s sensory and motor areas in the hand, so it’s the nerve involved in this condition. The other nerves don’t fit the presentation: the ulnar nerve services the little finger and the ulnar side of the ring finger and various hand muscles not typically impacted by carpal tunnel; the axillary nerve supplies the shoulder region; the radial nerve affects the back of the hand and wrist extension. Thus, the median nerve is the one involved in carpal tunnel syndrome.