Peripheral Neuropathy Symptoms: Causes, Testing and When to Be Seen

What it involves

MedlinePlus explains that peripheral nerves carry signals between the brain or spinal cord and the rest of the body. Peripheral neuropathy means one or more of those nerves are not working properly. It may affect a single nerve, a group of nerves, or nerves throughout the body, and what you feel depends on which nerves are involved.

Who this is for

• Adults with tingling, burning or numbness that begins in the toes or feet.
• Patients with diabetes who notice new foot pain or lost feeling.
• People whose legs buckle, who trip often or who struggle with buttons and small tasks.
• Anyone with a family history of nerve disease or a long history of heavy alcohol use.

What to expect

• Questions about where symptoms started, what makes them worse, your medicines, alcohol use and past illnesses
• A physical exam that checks feeling, strength, reflexes and balance
• Blood work, which is among the services the practice lists, to look for diabetes, vitamin and thyroid problems
• A referral for nerve studies if they are needed, and a plan to treat the cause and protect your feet

What it can feel like

The encyclopedia describes tingling or burning that often begins in the toes and feet, and sometimes deep pain in the feet and legs. Reduced feeling is just as important, because an injury, burn or sore can go unnoticed and balance can suffer. Muscles may weaken, twitch or cramp, and fine tasks such as buttoning a shirt become hard. Nerves that control organs can also be involved, causing lightheadedness on standing, digestive trouble, bladder changes or unusual sweating. The numbness and tingling guide covers the wider picture.

Common causes

MedlinePlus names diabetes, through long-term high blood sugar, as a common cause. The list also includes autoimmune disorders, chronic kidney disease, infections such as shingles and hepatitis C, low levels of vitamins B1, B6 and B12, an underactive thyroid, poor blood flow to the legs and long-term heavy alcohol use. Some medicines, chemical exposures and nerve pressure, as in carpal tunnel syndrome, can also play a role. Often no cause is found, and some nerve diseases run in families.

How the cause is looked for

A visit begins with your symptom history and an exam of feeling, strength and reflexes. MedlinePlus lists blood and urine tests to find a cause, and the practice offers blood work. Nerve conduction studies, electromyography and nerve or skin biopsy are other tests the encyclopedia describes, and these are arranged by referral rather than done in the office. Sugar control, thyroid function and vitamin levels are explained in the prediabetes and A1c page and the thyroid blood tests page.

Treatment starts with the cause

According to MedlinePlus, treating the underlying cause may improve symptoms. For diabetes that means controlling blood sugar, and for alcohol-related damage it means stopping drinking. A medicine that harms nerves may need to be changed, but never stop a prescribed medicine without asking. Vitamin replacement can help when levels are low. Pain medicines and some medicines also used for seizures or depression can ease nerve pain, though they usually do not restore lost feeling. Physical therapy, braces and balance work are arranged by referral.

Protecting your feet and your home

When feeling is reduced, small injuries become big ones. MedlinePlus advises wearing shoes at all times, checking inside them for debris, looking over both feet every day including between the toes, washing in lukewarm water and testing bathwater with your elbow. At home, remove loose rugs and cords, keep lighting good and add handrails and a non-slip bath mat. People with diabetes can read the diabetic foot care guide, which covers daily checks and when to call the same day.

Outlook, and when to act fast

The encyclopedia says the outlook depends on the cause and on how long the nerve damage has lasted. When the cause is found and treated it may be excellent, though some damage can be permanent, and numb feet can develop sores that do not heal. Contact a provider for any symptoms of nerve damage, because early treatment improves control. Nerve damage can also mask chest pain, so call 911 for sudden fatigue, sweating, shortness of breath, nausea or vomiting.

Sources

• MedlinePlus: Peripheral neuropathy (encyclopedia)