Polyneuropathy: what it is, what causes it and what helps

What polyneuropathy is

Polyneuropathy is the malfunction of many peripheral nerves at the same time. It can affect sensory nerves, which carry feeling, motor nerves, which work the muscles, and autonomic nerves, which control involuntary functions such as blood pressure.

The far ends of the longest nerves usually go first, so symptoms begin in the toes of both feet and spread slowly upward. The hands, if involved, follow later: the “stocking and glove” pattern. Its medical name is distal symmetric polyneuropathy, the most common form of neuropathy according to the American Academy of Neurology (AAN). Numbness, tingling and burning usually come first; weakness and unsteady walking can follow. The full symptom list.

How common it is. A 2020 review in American Family Physician puts peripheral neuropathy at 1 to 7 percent of the general population, higher over age 50. In a 2016 Dutch study of 1,310 people with an average age of 70, 5.5 percent had definite polyneuropathy, and almost half of those cases had never been diagnosed.

Polyneuropathy, mononeuropathy and mononeuritis multiplex

Multifocal motor neuropathy, a rare immune condition, weakens muscles in a patchy way, usually without numbness, most often starting in one hand.

Types of polyneuropathy

Three distinctions matter most here; types of neuropathy covers the rest.

• Which part of the nerve. Axonal neuropathies damage the axon, the nerve fiber itself, and come most often from toxic or metabolic causes such as diabetes, kidney disease, chemotherapy and alcohol. Demyelinating neuropathies damage myelin, the fiber’s insulating coat, as in Guillain-Barré syndrome and CIDP.
• How fast. In Guillain-Barré syndrome (GBS), the immune system attacks the nerves, and weakness “usually comes on quickly and worsens over hours or days.” Chronic forms develop over months to years. Chronic inflammatory demyelinating polyneuropathy (CIDP), considered the long-term form of GBS, worsens over at least eight weeks.
• Inherited or acquired. Charcot-Marie-Tooth disease, the most common inherited neuropathy, affects roughly 1 in 2,500 people, though estimates vary widely. More on Charcot-Marie-Tooth disease.

Causes, most common first

Many causes are treatable. The 2026 Standards of Care from the American Diabetes Association (ADA) advise considering other causes even in people who have diabetes.

• Diabetes and prediabetes. Diabetes is the leading cause of peripheral neuropathy in the US, says the National Institute of Neurological Disorders and Stroke (NINDS). In a 2021 review of 29 studies, most found neuropathy more often than expected in prediabetes too, mainly in small nerve fibers. Diabetic neuropathy.
• Alcohol. Excessive drinking is another common cause.
• Low vitamin B12, which can damage nerves even without anemia. Long-term metformin and acid-reducing medicines can lower it. Vitamin B12 and neuropathy. Too much vitamin B6 can cause polyneuropathy too.
• Chemotherapy and other medicines, including some drugs for HIV, infections, heart disease and seizures. Don’t stop a prescribed medicine on your own; ask the prescriber.
• Kidney disease. Most people on dialysis develop some form of peripheral neuropathy, NINDS notes.
• An underactive thyroid (hypothyroidism).
• Abnormal blood proteins and amyloidosis. Some blood disorders make an abnormal antibody called a paraprotein. In AL amyloidosis, parts of it build up in the heart, kidneys and nerves; a 2025 review stresses spotting it early in people with neuropathy.
• Infections, including HIV, hepatitis C and Lyme disease, and immune attacks such as GBS and CIDP.
• Inherited conditions, most often Charcot-Marie-Tooth disease, and rarely hereditary transthyretin amyloidosis.

When no cause is found

A polyneuropathy is called idiopathic when testing finds no cause. It is common: 25 to 46 percent of peripheral neuropathy in the 2020 American Family Physician review, and 46 percent of polyneuropathy in the Dutch study. The usual form, chronic idiopathic axonal polyneuropathy, usually progresses slowly, a 2016 review found. Ask which tests were done. If they find nothing, Mayo Clinic says, watchful waiting may be advised.

How polyneuropathy is diagnosed

Treatment

• Treat the cause. With diabetes, the ADA’s 2026 Standards advise optimizing glucose management to prevent or delay neuropathy in type 1 diabetes and to slow it in type 2. Thyroid hormone treats an underactive thyroid, and B12 replaces a deficiency. Stopping a medicine, with the prescriber’s agreement, or avoiding a toxin “can sometimes reverse the polyneuropathy,” Merck’s manual says.
• Calm an immune attack. GBS is treated in hospital with plasma exchange, which filters antibodies out of the blood, or intravenous immunoglobulin (IVIG), donated antibodies given by vein. NINDS says the two are “equally effective if started within two weeks.” CIDP is treated with corticosteroids, IVIG or plasma exchange.
• Treat nerve pain. Recommendations updated in 2025 by the Neuropathic Pain Special Interest Group (NeuPSIG) put tricyclic antidepressants, SNRI antidepressants such as duloxetine, and gabapentin or pregabalin first, with capsaicin and lidocaine skin treatments second. Results are modest, and each has side effects. How nerve pain is treated.
• Protect numb feet. Check them every day, and wear shoes and socks at all times, even indoors. The daily foot check.
• Stay steady. Physical therapy can help with weakness and balance problems. Braces, orthopedic shoes, a cane or a walker can make walking easier and safer.

Outlook and life expectancy

“How completely people recover depends on the cause of polyneuropathy,” Merck’s manual says. When the cause is corrected, NINDS notes, a neuropathy can sometimes resolve as nerves recover and regrow. Recovery is slow, though, and may be incomplete.

• Guillain-Barré syndrome can be life-threatening when it affects breathing, blood pressure or heart rate. Most people eventually recover, even from severe cases, though some are left with weakness, numbness, fatigue or pain.
• CIDP. About 90 percent improve with treatment and about half relapse, Cleveland Clinic says; life expectancy is typically normal.
• Charcot-Marie-Tooth disease. Most people have a normal life expectancy.
• Diabetic polyneuropathy. No treatment can yet reverse the nerve damage, the ADA’s 2026 Standards say, but glucose management can help slow it.

Life expectancy. There is no single figure. In a 2021 US study of 7,116 adults aged 40 and over, followed for a median of 13 years, those who had lost feeling in their feet on a monofilament test had higher death rates, with or without diabetes. That shows a link and can’t prove cause. How neuropathy can add risk, and what lowers it. What recovers, and what doesn’t.

When to get help urgently

• Go to an emergency department, or call 911, for weakness that spreads over hours or days, or for any new trouble breathing or swallowing. These can be signs of Guillain-Barré syndrome, which needs hospital care.
• Call 911 for sudden numbness or weakness in the face, an arm or a leg, especially on one side of the body, sudden trouble speaking, or sudden loss of balance. These can be signs of a stroke.
• Go to an emergency department, or call 911, for new numbness around the groin or bottom, or new bladder or bowel trouble, especially with back pain or leg weakness. These can be signs of pressure on the nerves at the base of the spine.
• Get seen the same day for a foot that turns warm, red and swollen without an injury. In a numb foot this can be Charcot foot, a weakening of the foot bones, or an infection. Keep weight off it until then.
• Call your doctor the same day if a cut, blister or bruise on a numb foot turns red, warm, swollen or painful, drains, or comes with a fever, or if it hasn’t started to heal after a few days.
• See your doctor promptly for numbness or weakness that hits one nerve after another, especially with weight loss or fever, which can mean vasculitis. The same goes for neuropathy that is worsening over weeks, is much worse on one side, or mainly causes weakness.

Common questions

Related reading

Small fiber neuropathy · Peripheral neuropathy medication · Alcohol-related neuropathy · Chemotherapy-induced neuropathy · Peroneal neuropathy · Neuropathy exercises