Arm · Nerve
Median Nerve
The median nerve runs down the arm to the hand, passing through the wrist's "carpal tunnel". When squeezed there it causes carpal tunnel syndrome — tingling and numbness in the fingers.
What it is
The median nerve is one of the main nerves of the arm, travelling from the shoulder region to the hand through a narrow passage at the wrist.
Where it runs
Down the front of the arm and through the carpal tunnel at the wrist into the hand.
What it does
Controls several muscles that move the thumb and forearm, and carries sensation from the thumb, index, middle and part of the ring finger.
When things go wrong
Common problems affecting the median nerve
- Carpal tunnel syndrome (compression at the wrist)
- Nerve injury from wrist trauma
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. New weakness or numbness, facial drooping, or loss of bladder or bowel control can be an emergency — call 999.
Did you know?
An interesting fact
Carpal tunnel syndrome — from pressure on the median nerve at the wrist — is one of the most common nerve compression problems.
Answers
Median Nerve: frequently asked questions
What is carpal tunnel syndrome?
It is tingling, numbness and sometimes weakness in the thumb and fingers, caused by the median nerve being squeezed as it passes through the wrist. Splints, activity changes and sometimes surgery can help.
Related nerves
Explore arm nerves
Sources
Where this is drawn from
- NHS — Nervous system
- Gray's Anatomy for Students
- TeachMeAnatomy — nervous system
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