A pinched nerve is the result of something inside or outside of your body pressing against a nerve. The compressed nerve then becomes inflamed, which causes symptoms.
The medical terms for a pinched nerve are nerve compression or nerve entrapment.
A pinched nerve can happen almost anywhere in your body. One of the more common places is your arm.
Keep reading to learn about the common (and uncommon) causes of a pinched nerve in your arm, and how it’s diagnosed and treated. We’ll also point you towards some exercises that can help relieve a pinched nerve, as well as prevention tips.
|Common causes||Less common causes|
|median nerve compression (carpal tunnel syndrome)||pronator syndrome|
|ulnar nerve compression (cubital tunnel syndrome)||anterior interosseous nerve syndrome|
|radial nerve compression||ulnar tunnel syndrome|
|radial tunnel syndrome||superficial sensory nerve compression|
|posterior interosseous syndrome|
The three main nerves in your arm and their approximate paths are:
- the median nerve, which runs down the center of your arm
- the radial nerve, runs down the thumb side of your arm
- the ulnar nerve, which runs down the little finger side of your arm
These nerves or their branches can get pinched in several places as they travel down your arm. Most often, this occurs near your elbow or your wrist, where bones and other structures form tunnels and small passageways your nerves must travel through.
Median nerve compression
Carpal tunnel syndrome (CTS) is the most common nerve compression syndrome. The median nerve gets compressed as it travels through the carpal tunnel in your wrist.
Extending and flexing your wrist can lead to compression by reducing the size of the tunnel. CTS is frequently caused by repetitive movements of your wrists.
Ulnar nerve compression
The second most common nerve compression syndrome is cubital tunnel syndrome.
The ulnar nerve can get compressed as it runs through the cubital tunnel or another tight spot around your elbow. It usually happens when you keep your arm bent for a long time, such as when you rest your arm on the window edge of your car while driving or lean on your elbows at a table.
Radial nerve compression
Near your elbow, the radial nerve branches into the posterior interosseous and superficial nerves. Both branches can be compressed commonly by repeatedly twisting your forearm.
Radial tunnel syndrome
The superficial branch of the radial nerve travels through the radial tunnel and several other tight spots around your elbow, where it can be compressed.
Posterior interosseous syndrome
The posterior interosseous nerve also passes through several tight spots in your forearm near your elbow, including the radial tunnel. It can be compressed as it travels through any of these places.
Less common causes
The median nerve can be compressed by the muscles in your forearm below your elbow.
The symptoms are the same as CTS, except the numbness can extend into your palm, and you may feel pain in your forearm and elbow. Unlike CPS, it usually doesn’t cause symptoms at night.
Anterior interosseous nerve syndrome
This motor nerve is a branch of the median nerve. Compression occurs at one or more sites in your forearm. It causes weakness in your thumb and index finger, making it hard to grip a pencil or make the “OK” sign.
Other symptoms are weakness when twisting your forearm and vague forearm pain.
Ulnar tunnel syndrome
This uncommon condition occurs when the ulnar nerve is compressed in a tunnel on the pinkie side of your wrist. Usually, ulnar tunnel syndrome is caused by a ganglion cyst or chronic repetitive wrist trauma such as a cyclist’s gripping a handlebar.
The symptoms in your ring finger and pinkie can be motor, sensory, or both depending on the site of compression. Unlike with cubital tunnel syndrome, the back of your hand isn’t affected.
Superficial sensory nerve compression
The radial nerve becomes more superficial near your wrist. The symptoms are numbness and tingling on the top of the thumb side of your hand, sometimes with forearm and wrist pain.
Anything that fits tightly around your wrist such as handcuffs or a watch can compress it. Leaning on your forearm for a long time is another cause.
Yes, you can pinch a nerve in your armpit.
Your axillary nerve starts in your neck and runs through your armpit before crossing over your upper arm bone (humerus). It branches into a motor nerve to your shoulder muscles (deltoid and teres minor) and a sensory nerve to your shoulder.
Your axillary nerve can be pinched by:
- a dislocated shoulder
- a humerus fracture
- continuous armpit pressure, such as from using a crutch
- repeated overhead movement, such as pitching a baseball or hitting a volleyball
- injury to the nerve during rotator cuff surgery
Possible symptoms include:
- shoulder ache
- arm muscle fatigue while performing overhead movements
- difficulty lifting or rotating your arm
- numbness and tingling on the side and back of your upper arm
A nerve becomes inflamed when it’s pinched, which causes varying symptoms depending on the type of nerve that’s involved.
Sensory nerves send information about things your body senses to your brain. When a sensory nerve is pinched, the symptoms might include:
Sensory nerve symptoms
- a “pins and needles” tingling sensation
- loss of sensation
Motor nerve symptoms
Motor nerves send signals from your brain to your body, especially your muscles, telling it how to react to the information. Symptoms of a pinched motor nerve include:
- muscle weakness
- loss of movement
Some nerves have both sensory and motor functions. When these are pinched, symptoms of both types can occur.
Carpal tunnel syndrome symptoms
The medial nerve is a sensory nerve for your thumb, index and middle fingers, and half of your ring finger.
CTS causes numbness, tingling, and pain in those areas. The symptoms may radiate up into your arm and shoulder. The symptoms are frequently worse at night.
The medial nerve is also a motor nerve to your thumb, so CTS can cause thumb weakness and clumsiness too. This can make it hard to grip things. As CTS becomes more severe, you may notice muscle wasting under your thumb (thenar eminence).
Cubital tunnel syndrome symptoms
The ulnar nerve supplies sensation and motor to your little finger and half of your ring finger.
Compression causes numbness and tingling (but not pain) in those fingers and weakness in the small muscles in your hand. Eventually, muscle wasting can occur, moving your fingers to abnormal positions.
Radial tunnel syndrome symptoms
The superficial branch is a sensory nerve. It’s not very deep, so it’s easily compressed by anything that puts pressure on your forearm. When compressed, it causes an achy pain in your forearm that may radiate to your elbow.
The symptoms are very similar to tennis elbow (lateral epicondylitis).
Posterior interosseous syndrome symptoms
This is a motor nerve that serves the small muscles in your fingers, thumb, and wrist. Compression makes it difficult to extend your fingers and thumb straight out. It also affects your ability to turn the thumb side of your wrist toward your forearm.
A doctor may be able to diagnose a common pinched nerve, like CTS, based only on your symptoms and an examination.
When needed, a doctor may also use one or more of the following tests to make or confirm a diagnosis.
- X-rays. They’re not often helpful but may reveal another diagnosis, like a fracture.
- MRI. This is occasionally used to clarify a diagnosis or reevaluate a pinched nerve that’s not getting better.
- Electromyography. This test shows electrical activity in a muscle.
- Nerve conduction study. This test shows the speed of nerve signals.
- Ultrasound. This is sometimes used to evaluate a nerve.
Conservative therapy for a pinched nerve is always tried first with the goal of reducing pain and improving function.
It’s important to rest your arm as much as possible to allow it to heal.
Over-the-counter pain medication
Anti-inflammatory medication such as ibuprofen (Advil) or naproxen (Aleve) can reduce the inflammation in the nerve, relieving symptoms.
Heat or ice
Heat or ice applied over the pinched nerve in 20-minute sessions can help relieve your symptoms. Be careful not to burn or freeze your skin if your sensation is decreased.
A splint may be used to immobilize your wrist, elbow, or arm, or to assist weak muscles.
CTS can be treated with a one-time corticosteroid injection to reduce inflammation and ease the pressure on your nerve. It usually only works for about a month.
Surgery to release the pressure on the nerve is routinely used for most nerve compression syndromes. You might be a good candidate for surgery if:
- symptoms don’t improve after three to six months of conservative therapy
- symptoms are severe
- muscle wasting occurs
Recovery time varies depending on a number of factors, including:
- the nerve involved
- the seriousness of the injury
- how the injury responds to conservative therapy
- the need for surgery
- the work or activities you’ll return to
Pinched nerves due to temporary pressure on a superficial nerve usually resolve on their own within hours. Those caused by a ganglion cyst won’t improve until the cyst is removed.
Stretches to maintain flexibility or to maintain or build muscle strength can be very helpful for pinched nerve symptom relief, healing, and prevention.
The following articles describe stretches and exercises for your arms and wrists:
- stretches for wrists and hands
- exercises for treating carpal tunnel
- 5 good yoga stretches for your arms
- cubital tunnel syndrome exercises to relieve pain
Before starting an exercise program, talk to a doctor to be sure it’s safe and won’t cause further injury. Your doctor can also refer you to a physical therapist who can design a routine specifically for you.
Stop an exercise immediately if it causes significant discomfort or pain.
Here are some things you can do to prevent a pinched nerve from recurring:
- Minimize or avoid the repetitive movements and activities that cause it.
- If your injury was work related, you may have to change how you use your hands and arms to perform your job.
- If you can’t do your work without the repetitive movements, you might need to consider changing jobs.
- Change your hand and arm position frequently while performing an activity.
- Take frequent breaks to rest or stretch your wrists and arms.
- Avoid any activities and positions that put pressure on superficial nerves.
- Make sure you aren’t putting pressure on superficial nerves while sleeping.
- Rest your arms as much as possible throughout the day.
Any of the nerves in your arm can become pinched if they’re compressed by surrounding structures. It’s most likely to happen where the nerve travels through a tunnel or other small space.
Symptoms depend on the nerve type and may include numbness and pain, muscle weakness, or both. Initial treatment is with conservative therapy, but surgery is often needed to remove the pressure from the nerve.
The best way to prevent recurrence of a pinched nerve is to avoid the activity or repetitive movements that initially caused it.