Peripheral neuropathy

Peripheral neuropathy happens when the peripheral nerves, which are located outside of the brain and spinal cord, are damaged. This condition often causes weakness, numbness and pain, usually in the hands and feet. It also can affect other areas and body functions, including digestion and urination.

The peripheral nervous system sends information from the brain and spinal cord, also called the central nervous system, to the rest of the body through motor nerves. The peripheral nerves also send sensory information from the skin, tendons, joints and organs to the central nervous system through sensory nerves.

Peripheral neuropathy can result from traumatic injuries, infections, metabolic conditions, autoimmune diseases, inherited causes and exposure to toxins. One of the most common causes of neuropathy is diabetes.

People with peripheral neuropathy usually describe the pain as stabbing, burning or tingling. Sometimes symptoms get better, especially if caused by a condition that can be treated. Medicines can reduce the pain of peripheral neuropathy.

Every nerve in the peripheral system has a specific job. Symptoms of peripheral neuropathy depend on the types of nerves affected. Nerves are divided into:

• Sensory nerves that receive sensation information, such as temperature, pain, vibration or touch, from the skin.
• Motor nerves that control muscle movement.
• Autonomic nerves that control functions such as blood pressure, sweating, heart rate, digestion and bladder function.

Symptoms of peripheral neuropathy might include:

• Gradual onset of numbness, prickling or tingling in the feet or hands. These sensations can spread upward into the legs and arms.
• Sharp, jabbing, throbbing or burning pain.
• Extreme sensitivity to touch.
• Pain during activities that shouldn't cause pain, such as pain in your feet when putting weight on them or when they're under a blanket.
• Lack of coordination and falling.
• Muscle weakness.
• Feeling as if you're wearing gloves or socks when you're not.
• Loss of the ability to move if motor nerves are affected.

If autonomic nerves are affected, symptoms might include:

• Heat intolerance.
• A lot of sweating or not being able to sweat.
• Trouble with bowel, bladder or digestive system.
• Drops in blood pressure, causing dizziness or lightheadedness.

If peripheral neuropathy affects one nerve, it's called mononeuropathy. If it affects two or more nerves in different areas, it's called multiple mononeuropathies. If it affects many nerves all over the body, it's called polyneuropathy. Carpal tunnel syndrome is an example of mononeuropathy. Most people with peripheral neuropathy have polyneuropathy.

When to see a doctor

Seek medical care right away if you notice tingling, weakness or pain in your hands or feet. Early diagnosis and treatment give you the best chance of managing your symptoms and preventing further damage to your peripheral nerves.

Peripheral neuropathy is nerve damage caused by several different conditions. Health conditions that can cause peripheral neuropathy include:

• Autoimmune diseases. These include Sjogren syndrome, lupus, rheumatoid arthritis, Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy and vasculitis. Also, some cancers related to the body's immune system can cause polyneuropathy. These are a form of the autoimmune disorder called paraneoplastic syndrome.
• Diabetes and metabolic syndrome. These are the most common causes. Among people with diabetes, more than half develop some type of neuropathy.
• Infections.These include certain viral or bacterial infections, including Lyme disease, shingles, hepatitis B and C, leprosy, diphtheria, and HIV.
• Inherited conditions. Conditions such as Charcot-Marie-Tooth disease are hereditary types of neuropathies that run in families.
• Tumors.Growths that are cancerous, also called malignant—or noncancerous, also called benign—can happen on or press on nerves.
• Bone marrow conditions. These include conditions such as monoclonal gammopathies, caused by a protein in the blood that isn't usually there. Other conditions are lymphoma, the rare disease amyloidosis and a rare form of myeloma that affects the bones.
• Other health concerns. These include metabolic conditions such as kidney disease or liver disease and an underactive thyroid, also known as hypothyroidism.

Other causes of peripheral neuropathy include:

• Alcohol use disorder. Less healthy dietary choices made by people with alcohol use disorder, also known as alcoholism, and poor absorption of vitamins caused by alcohol use can lead to low amounts of essential vitamins in the body.
• Exposure to poisons. Toxic substances include industrial chemicals and heavy metals such as lead and mercury.
• Medicines. Certain medicines, especially chemotherapy used to treat cancer, can cause peripheral neuropathy.
• Injuries or pressure on nerves. Injuries, such as from motor vehicle accidents, falls or sports injuries, can sever or damage peripheral nerves. Nerve pressure can result from having a cast, using crutches or repeating a motion, such as typing many times.
• Low vitamin levels. B vitamins, including B-1, B-6 and B-12, copper and vitamin E are crucial to nerve health.

Sometimes, no cause can be identified. This is called idiopathic peripheral neuropathy.

Peripheral neuropathy risk factors include:

• Diabetes, especially if sugar levels are not well managed.
• Obesity.
• Metabolic syndrome.
• Alcohol misuse.
• Low levels of vitamins in the body, especially vitamin B-12.
• Infections, such as Lyme disease, shingles, hepatitis B and C, and HIV.
• Autoimmune diseases, such as rheumatoid arthritis and lupus, in which the immune system attacks the body's tissues.
• Kidney, liver or thyroid disorders.
• Exposure to toxins.
• Repetitive motion, such as those done in certain jobs.
• Family history of neuropathy.

Complications of peripheral neuropathy can include:

• Burns, skin injuries and wounds on the feet. You might not feel temperature changes or pain on parts of your body that are numb.
• Infection. Your feet and other areas that lack sensation can become injured without your knowing. Check these areas regularly, wear close-toed, well-fitting shoes and treat minor injuries before they become infected, especially if you have diabetes.
• Falls. Weakness and loss of sensation may be associated with a lack of balance and falling. Installing handrails in the bathroom, using canes or walkers when needed, and ensuring you walk only in well-lit rooms can decrease fall risk.

Manage underlying conditions

The best way to prevent peripheral neuropathy is to manage medical conditions that put you at risk.

Make healthy lifestyle choices

These habits support your nerve health:

• Eat a diet rich in fruits, vegetables, whole grains and lean protein to keep nerves healthy. Protect against low levels of vitamin B-12 by eating meats, fish, eggs, low-fat dairy foods and fortified cereals. If you're vegetarian or vegan, fortified cereals are a good source of vitamin B-12, but talk with your healthcare professional about B-12 supplements.
• Exercise regularly. With your healthcare professional's OK, try to get at least 30 minutes to one hour of exercise at least three times a week.
• Avoid factors that may cause nerve damage. These factors can include repetitive motions, exposure to toxic chemicals, smoking and drinking too much alcohol.

Peripheral neuropathy has many possible causes. Besides a physical exam, which may include blood tests, diagnosis usually requires:

• A detailed medical history. Your healthcare professional looks at your medical history. This history includes your symptoms, lifestyle, exposure to toxins, drinking habits, and any family history of nervous system or neurological diseases.
• Neurological exam. Your healthcare professional might check your tendon reflexes, muscle strength and tone, ability to feel certain sensations, and balance and coordination.

Tests

Your healthcare professional may order tests, including:

• Blood tests. These can detect low levels of vitamins, diabetes, signs of inflammation or metabolic issues that can cause peripheral neuropathy.
• Imaging tests. CT or MRI scans can look for herniated disks, pinched nerves, also called compressed nerves, growths or other conditions affecting the blood vessels and bones.

• Nerve function tests. Electromyography (EMG) measures and records electrical activity in your muscles to find nerve damage. A thin needle (electrode) is inserted into the muscle to measure electrical activity as you contract the muscle.

  During EMG, you also typically have a nerve conduction study. Flat electrodes are placed on the skin and a low electric current stimulates the nerves. Your healthcare professional records how the nerves respond to the electric current.

• Other nerve function tests. These might include an autonomic reflex screen. This test records how the autonomic nerve fibers work. Other tests can include a sweat test that measures your body's ability to sweat and a sensory test that records how you feel touch, vibration, cooling and heat.
• Nerve biopsy. This involves removing a small portion of a nerve, usually a sensory nerve, to try to find the cause of the neuropathy.
• Skin biopsy. Your healthcare professional removes a small portion of skin to check the number of nerve endings.

Treatment goals are to manage the condition causing your neuropathy and to improve symptoms. If your lab tests do not find a condition causing the neuropathy, your healthcare professional might recommend watchful waiting to see if your neuropathy stays the same or gets better.

Medicines

Medicines can be used to treat conditions associated with peripheral neuropathy. There also are medicines used to improve peripheral neuropathy symptoms. These medicines include:

• Pain relievers. Medicines available without a prescription, such as nonsteroidal anti-inflammatory drugs, can improve mild symptoms.
• Antiseizure medicines. Medicines such as gabapentin (Gralise, Neurontin, Horizant) and pregabalin (Lyrica), developed to treat epilepsy, often improve nerve pain. Side effects can include drowsiness and dizziness.

• Topical treatments. Lidocaine cream, which you can get without a prescription, can be applied to the skin.

  Lidocaine patches are another treatment you apply to the skin to improve pain. Side effects can include drowsiness, dizziness and numbness at the site of the patch.

• Antidepressants. Certain tricyclic antidepressants, such as amitriptyline and nortriptyline, can help improve pain. These medicines interfere with chemical processes in the brain and spinal cord that cause you to feel pain.

  The serotonin and norepinephrine reuptake inhibitor duloxetine (Cymbalta) and the extended-release antidepressants venlafaxine (Effexor XR) and desvenlafaxine (Pristiq) also might improve peripheral neuropathy pain caused by diabetes.

  Side effects of antidepressants may include dry mouth, nausea, drowsiness, dizziness, changes in appetite, weight gain and constipation.

Therapies

Various therapies and procedures might help with the symptoms of peripheral neuropathy.

• Scrambler therapy. This treatment uses electrical impulses to send nonpain messages to the brain. These messages replace the pain messages the nerves send to the brain. The goal is to retrain the brain to think there is no pain.
• Spinal cord stimulation. This type of therapy works through devices put into the body. These devices are called neurostimulators. They send low-level electrical impulses that can block pain signals from reaching the brain.
• Plasma exchange, steroids and intravenous immune globulin. These treatments are often used if inflammation or autoimmune conditions are causing neuropathy with weakness, numbness or loss of balance. These therapies are not used to treat pain alone.
• Physical therapy. Physical therapy can help improve your ability to move if you have muscle weakness or balance issues. You also may need hand or foot braces, a cane, a walker, or a wheelchair.
• Surgery. Neuropathies caused by pressure on nerves, such as from tumors, might require surgery.

Some people with peripheral neuropathy try complementary treatments for relief. Researchers haven't studied these techniques as thoroughly as they have most medicines. But the following therapies have shown some promise:

• Acupuncture. Inserting thin needles into various points on your body might lessen peripheral neuropathy symptoms. You might need multiple sessions before you see improvement. Acupuncture is generally considered safe when done by a certified acupuncturist using sterile needles.
• Alpha-lipoic acid. This has been used as a treatment for peripheral neuropathy in Europe for years and there is some evidence that it can be helpful for those with painful diabetic neuropathy. Discuss using alpha-lipoic acid with your healthcare professional because it can affect blood sugar levels. Other side effects can include upset stomach and skin rash.
• Amino acids. Amino acids, such as acetyl-L-carnitine, might benefit people who have undergone chemotherapy and people with diabetes. Side effects might include nausea and vomiting.

To help you manage peripheral neuropathy:

• Take care of your feet, especially if you have diabetes. Check daily for blisters, cuts or calluses. Wear soft, loose cotton socks and padded shoes. You can use a semicircular hoop, which is available in medical supply stores, to keep bedcovers off hot or sensitive feet.
• Exercise. Regular exercise, such as walking three times a week, can lower neuropathy pain, improve muscle strength and help manage blood sugar levels. Gentle routines such as yoga and tai chi also might help. If you have painful neuropathy in your feet, you may want to try pool-based exercise such as swimming.
• Quit smoking. Cigarette smoking can cause problems with circulation. This increases the risk of foot problems and other neuropathy complications.
• Eat healthy meals. Good nutrition is especially important to make sure that you get important vitamins and minerals. Include fruits, vegetables, whole grains and lean protein in your diet.
• Avoid excessive alcohol. Alcohol can make peripheral neuropathy worse.
• Monitor your blood sugar levels. If you have diabetes, this will help manage your blood sugar and might help improve your neuropathy.

You're likely to start by seeing your primary healthcare professional. You may then be referred to a doctor trained in nervous system conditions, called a neurologist.

Here's information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if you need to do anything in advance, such as fasting for a specific test. Make a list of:

• Your symptoms, including any that may seem like they're not related to your reason for scheduling the appointment.
• Key personal information, including recent stresses or major life changes, family medical history, and alcohol use.
• All medicines, vitamins and other supplements you take, including doses.
• Questions to ask your healthcare professional.

Take a family member or friend along, if possible, to help you remember the information you get.

For peripheral neuropathy, basic questions to ask your healthcare professional include:

• What's the most likely cause of my symptoms?
• Are there other possible causes?
• What tests do I need?
• Is this condition short-term or long-lasting?
• What are the treatments, and which do you recommend?
• What side effects can I expect from treatment?
• Are there alternatives to the approach you're suggesting?
• I have other health conditions. How can I best manage them together?
• Do I need to limit activities?
• Are there brochures or other printed material I can take with me? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, such as:

• Do you have health conditions, such as diabetes or kidney disease?
• When did your symptoms begin?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• Does anything seem to make your symptoms better?
• What, if anything, appears to worsen your symptoms?
• Does anyone in your family have symptoms similar to yours?
• Have you fallen in the past year?
• Have you had any injuries to your feet?