Median Nerve

What is your median nerve?

Your median nerve helps you move your forearm, wrist, hand and fingers. It also provides sensation to your forearm and certain parts of your hand. (Your forearm is the lower part of your arm that extends from your elbow to your hand.) Pressure on your median nerve can cause carpal tunnel syndrome and other health problems.

If you experience pain, numbness or other sensations in your forearm or wrist that don’t go away, reach out to your healthcare provider. They’ll be able to determine what’s going on and develop a treatment plan for you.

What is the purpose of your median nerve?

Your median nerve provides sensory and motor (movement) functions to your forearm, wrist and hands. The nerve starts at your armpit, but its functions all take place in your forearm or hand.

Your median nerve stimulates muscles in your forearm, allowing you to:

• Bend and straighten your wrists, thumbs and first three fingers
• Rotate your forearm and hand to turn your palm downward

Your median nerve is also responsible for touch, pain and temperature sensations to the:

• Bottom (palm) side of your thumb, index and middle fingers, and part of your ring finger
• Forearm
• Thumb side of your palm
• Top (nail bed) side of your index and middle fingers

Where is your median nerve?

Your median nerve is one of five nerve branches of your brachial plexus. This complex network of nerves helps you move your shoulders, arms and hands. It also sends sensory information. Your brachial plexus begins as nerve roots from the cervical spine in your neck. The nerves travel behind your collarbone (clavicle) through your armpit (axilla).

You have a left and right median nerve — one for each side of your body. Your median nerve starts at your armpit and:

• Connects to nerve roots in your brachial plexus that run from your C5 to C8 cervical vertebrae and T1 thoracic vertebra
• Crosses in front of your brachial artery and goes under your bicipital aponeurosis, a broad band of connective tissue in your cubital fossa (triangular space opposite your elbow joint)
• Enters your hand through your carpal tunnel, a space in your wrist that holds your median nerve and tendons
• Runs along the inside of your upper arm between your bicep and triceps tendons, next to your brachial artery
• Travels with your ulnar nerve down your forearm, where it branches into smaller nerves

What are your median nerve branches?

Your median nerve branches include:

• Deep (volar interosseous) branch. This controls deeper muscles in the front part of your forearm.
• Muscular branch. This controls movement in your forearm’s superficial muscles, close to your skin.
• Palmar branch. This sends sensory information to and from your palm, thumb and some of your fingers.

What conditions and disorders affect your median nerve?

Pressure on your median nerve can cause a pinched nerve (nerve entrapment) or neuropathy (nerve damage). You may also develop a nerve compression syndrome, like:

• Anterior interosseous nerve syndrome. Damage to your anterior interosseous nerve (a motor branch of your median nerve) causes weakness or paralysis in your thumb and index finger.
• Carpal tunnel syndrome. Tissue swelling inside your carpal tunnel puts pressure on your median nerve. You may experience finger pain, wrist pain and numbness.
• Pronator teres syndrome. Your pronator teres muscle near your elbow pinches your median nerve. This condition causes dull, aching pain in your forearm.

What are the signs of median nerve problems?

Signs of a pinched median nerve include:

• Hand or wrist pain, numbness, weakness or tingling
• Hand pain that wakes you up at night
• Pain, burning or tingling sensation in your forearm
• Problems grasping items, writing or using a keyboard
• Tenderness or pain in your elbow or forearm
• Loss of muscle in your thumb (a rare symptom)

When should I talk to my healthcare provider?

You should call your healthcare provider if you experience:

• Difficulty picking up or holding on to items
• Pain, numbness or weakness in your forearm, wrist, thumb or fingers
• Problems performing everyday tasks like buttoning a shirt
• Unexplained elbow, forearm or wrist pain