Numb Hands

Diagram showing hand sensation patterns from radial, ulnar, and median nerves
Figure 1: Compression on a nerve can cause numbness in hands. This image shows the nerves that supply sensation to the hand.

Carpal tunnel syndrome is a common condition associated with numbness in the hands. However, it is not the only cause of hand numbness. Other causes can include nerve compression, peripheral neuropathy, fibromyalgia, myofascial pain syndrome, medications, nutritional deficiencies, multiple sclerosis, stroke, and disorders of the brain or spinal cord.

Causes

Compression Neuropathy

Compression neuropathy is pressure on a nerve anywhere along its course. In addition to numbness, compression neuropathy can cause weak or twitchy muscles. The pressure may come from many sources, including bleeding or swelling after injury, a displaced or angled fracture, thickened tendon lining, fascia, an abnormally located muscle, soft tissue masses, or ganglion cysts.

Ulnar Nerve Compression at the Wrist: Guyon Syndrome

This causes numbness and tingling typically on the pinky-finger side of the hand. The back side of the hand is usually normal. Severe cases can have hand and grip weakness, especially when trying to separate the fingers. The ability to bend the ring and small fingertips remains.

Ulnar Nerve Compression at the Elbow: Cubital Tunnel Syndrome

This condition typically has the same symptoms as Guyon syndrome, but also includes numbness on the back of the hand on the pinky side. There can also be pain at the inside portion of the elbow. Severe cases can cause hand and grip weakness when separating the fingers, bending the ring and small fingertips, or bending the wrist.

Radial Nerve Compression in the Forearm or Wrist

The radial nerve may be compressed in either side of the forearm. Proximal compression of the motor branch, called the posterior interosseous nerve, is called radial tunnel syndrome. This can cause achiness or vague pain in the back of the forearm and may worsen when straightening the wrist or finger. It can be challenging to diagnose because nerve conduction studies and imaging may be normal.

When the radial nerve branch is compressed, it is typically a sensory-only problem. This nerve can be injured by cuts, IV placement, handcuffs, or during surgery on the radial bone.

Median Nerve Compression at the Wrist: Carpal Tunnel Syndrome

This causes numbness and tingling in the thumb, index, and middle fingers. Other fingers, and sometimes the whole hand, may feel numb, although the small finger should have normal feeling when specifically tested. Severe cases can result in weakness when lifting the thumb away from the hand. Symptoms are often worse at night or after the wrist has been bent for a long time.

Median Nerve Compression at the Elbow

The numbness in this condition is similar to carpal tunnel syndrome in the fingers. There is also numbness in the palm near the thumb, which is not present in carpal tunnel syndrome. Sometimes there is weakness when bending the index and middle fingers or bending the tip of the thumb.

Diagram showing spinal nerve distribution to the hands
Figure 2: The nerves in the neck travel down the arms to connect to the muscles and skin in the arms and hands. Pressure on these nerves can cause numbness in hands.

Pressure on Nerves in the Neck

Pressure on nerves in the neck can be caused by arthritis, diseases, infections, tumors, blood vessel abnormalities, and other spinal cord conditions. In addition to numbness, symptoms may include weak muscles and decreased reflexes in the arm and forearm, and sometimes the legs. Neck-related nerve pressure is more likely to include radiating arm pain. Sometimes a nerve may have pressure in more than one area, which is called “double crush.” Pressure on a nerve may require surgery to get relief.

Peripheral Neuropathy

In peripheral neuropathy, the very ends of the nerves in the hands and feet are affected. There may or may not be pain, and the numbness is often constant. Diabetes, alcoholism, and older age are common known causes. Poisoning from metals and industrial compounds are also possible causes.

Peripheral neuropathy typically follows a “stocking-glove” pattern, with numbness moving up from the toes to the legs. By the time numbness progresses to the mid-calf, the fingers and hands may become involved. It can happen on both sides of the body and often affects all nerves to the feet or hands in a similar amount.

Diagram showing nerve pathways from the spine to the fingers
Figure 3: Nerve pathways from the spine to the fingers. Nerves can be compressed anywhere from the neck down.

Fibromyalgia

People with fibromyalgia may be more likely than others to develop carpal tunnel syndrome and may seek surgical treatment to release pressure in the carpal tunnel. Fibromyalgia can cause persistent pain in many areas of the body, along with fatigue, headaches, bowel problems, depression, sleep problems, and other generalized symptoms.

Myofascial Pain Syndrome

Myofascial pain syndrome can also cause numb hands and forearms, often with aches and pain. Although symptoms may be felt in the hands, the muscles causing the problem are usually in the neck and shoulder region. Symptoms are usually stiffness and may be associated with frequent headaches. There is no hand surgery to correct or improve symptoms from this condition.

Medications

Certain medications, including some cancer treatment drugs, are known to cause tingling and numbness in the hands. Some cause temporary numbness that goes away after chemotherapy is complete. Others may cause permanent numbness.

Other Causes

  • Nutritional deficiencies, such as vitamin B1, B6, or B12 deficiency
  • Multiple sclerosis
  • Stroke
  • Disorders of the brain and spinal cord

Diagnosis

The pattern of symptoms can help determine whether the cause is pressure on a nerve, a disease, medications, or another condition. For many of these disorders, a thorough history and physical exam are most important to narrow down or make a diagnosis. Further tests such as x-rays, MRI, nerve tests such as EMG, ultrasound, blood tests, or a spinal tap may be used to help confirm a diagnosis.

Treatment

Specific treatment recommendations can be made once the diagnosis is clear. You may also be referred to other specialists, such as a neurologist, rheumatologist, pain management specialist, or other health care provider. When weakness or stiffness is present, hand therapy may be helpful. A hand therapist can provide strengthening exercises. Wrist or elbow braces can often improve positional numbness. Some compression neuropathies can be treated with steroid injections, also called cortisone shots.

When non-operative treatments have failed, surgical decompression can be considered. Symptom improvement depends on how long the pressure has been present, how severe the pressure is, and other patient factors. Some problems can be fully treated. Other times, not all numbness or weakness will go away with treatment. Nerve injury can sometimes be permanent. Early evaluation by a hand surgeon may reduce the chance of permanent numbness, tingling, or weakness.

This mobile-friendly version is adapted from patient education content originally provided by the American Society for Surgery of the Hand.