Peripheral Neuropathy: Symptoms, Causes and How It Is Diagnosed

Pins and needles in your toes, feet that feel like they are wrapped in cotton, burning pain at night or a sense that you are walking on pebbles. These are some of the ways people describe peripheral neuropathy, one of the most common reasons patients see a neurologist. Neuropathy can be mild and slow, or it can progress and affect balance, safety and quality of life. Finding the cause is important, because some causes are treatable and early treatment can prevent further nerve damage.

What Is Peripheral Neuropathy?

The peripheral nervous system is the network of nerves outside the brain and spinal cord. It carries sensation from the skin to the brain, movement commands from the brain to the muscles, and automatic signals that control functions such as blood pressure, sweating and digestion. Neuropathy means damage or dysfunction of these nerves.

Neurologists describe neuropathy in several ways:

• Polyneuropathy: many nerves are affected, usually symmetrically, starting in the longest nerves to the feet.
• Mononeuropathy: a single nerve is affected, as in carpal tunnel syndrome.
• Small fiber neuropathy: mainly affects thin fibers carrying pain and temperature, often causing burning pain with a normal-looking exam.
• Autonomic neuropathy: affects the nerves that control internal organs.

Common Symptoms

Symptoms depend on which nerve fibers are involved. In the most common form, symptoms start in the toes and feet and slowly move upward, later involving the fingertips, a pattern often called "stocking and glove."

Sensory symptoms

• Numbness or reduced feeling.
• Tingling, prickling or "pins and needles."
• Burning, stabbing or electric-shock pains, often worse at night.
• Extreme sensitivity to touch, so that bed sheets feel painful.
• Loss of balance, especially in the dark or with eyes closed.

Motor symptoms

• Weakness in the feet or hands, tripping or difficulty opening jars.
• Muscle cramps or twitching, and thinning of muscles in the feet or hands.

Autonomic symptoms

• Dizziness when standing, abnormal sweating, digestive or bladder problems.

Because numb feet may not feel injuries, cuts and blisters can go unnoticed. In people with diabetes this can lead to serious foot infections, which is why daily foot checks are recommended.

What Causes Peripheral Neuropathy?

There are many possible causes, and sometimes more than one is present.

• Diabetes and prediabetes: the most common cause in the United States. Long-standing high blood sugar damages nerves and the small blood vessels that feed them.
• Vitamin deficiencies: especially vitamin B12, which may be low in older adults, after stomach surgery, in strict vegetarians and in people taking metformin or acid-reducing medications for a long time.
• Alcohol: heavy, long-term use is toxic to nerves and often accompanies poor nutrition.
• Medications: certain chemotherapy drugs and some other medications can cause neuropathy.
• Thyroid and kidney disease.
• Autoimmune and inflammatory conditions, including some that respond well to immune treatment.
• Abnormal blood proteins related to certain blood disorders.
• Inherited neuropathies, such as Charcot-Marie-Tooth disease, which may run in families and cause high arches or hammertoes.
• Infections, such as shingles, Lyme disease, hepatitis C or HIV.
• Compression or injury of individual nerves.

In a meaningful number of people, no specific cause is found despite a thorough evaluation. This is called idiopathic neuropathy. It tends to progress slowly, and symptoms can still be treated.

How Neurologists Diagnose Neuropathy

History and examination

Your neurologist will ask how symptoms began, how fast they are changing, your medical conditions, medications, alcohol use, diet and family history. The examination checks sensation to touch, pin, vibration and position, reflexes, strength and balance. The pattern of findings often points toward particular causes.

Blood tests

Typical tests include blood sugar and hemoglobin A1c, vitamin B12, thyroid function, kidney and liver function and tests for abnormal blood proteins. Additional tests are ordered based on the clinical picture.

EMG and nerve conduction studies

Electrodiagnostic testing confirms whether neuropathy is present, shows whether it mainly affects the nerve fibers or their myelin coating, and identifies nerve compression such as carpal tunnel syndrome. See our guide on what to expect during an EMG and nerve conduction study.

Other tests

When small fiber neuropathy is suspected and nerve conduction studies are normal, a small skin biopsy can measure the density of nerve endings. Occasionally, spinal imaging, autonomic testing, genetic testing or a nerve biopsy is needed.

Treatment Options

Treat the underlying cause

Good blood sugar control can slow diabetic neuropathy. Vitamin B12 replacement can stop and sometimes reverse deficiency-related nerve damage. Stopping alcohol, adjusting a problem medication or treating thyroid disease can make a real difference. Inflammatory neuropathies may respond to immune therapies.

Relieve nerve pain

Several medications can reduce neuropathic pain, including certain antidepressants (such as duloxetine or low-dose tricyclics) and anti-seizure medications (such as gabapentin or pregabalin). Topical treatments, such as lidocaine or capsaicin, may help localized pain. Your neurologist will balance benefits against side effects like drowsiness or dizziness, especially in older adults.

Protect your feet and balance

• Inspect your feet daily and wear well-fitting, protective shoes.
• Use night lights and remove trip hazards at home.
• Consider physical therapy for strength and balance training.
• Stay active; regular walking and exercise support nerve and vascular health.

Can Neuropathy Be Reversed?

It depends on the cause and on how long the nerves have been affected. Nerves can regrow slowly once the source of injury is removed, so neuropathy caused by vitamin B12 deficiency, a medication or nerve compression may improve over months. Long-standing nerve damage is less likely to reverse completely, but treatment can often stop it from getting worse and make symptoms much easier to live with. This is one more reason not to delay an evaluation.

When to See a Neurologist

Make an appointment if you have persistent numbness, tingling, burning or weakness, especially if it is spreading or affecting your balance. Seek urgent care if weakness develops quickly over days, particularly if it rises from the legs into the arms or affects breathing or swallowing, since this can signal Guillain-Barré syndrome. Sudden numbness or weakness on one side of the body may be a stroke and needs emergency evaluation.

Neuropathy Care in Westwood, NJ

Peripheral neuropathy is a clinical interest of Dr. David D. Van Slooten, who is board certified in Electrodiagnostic Medicine. Our office performs EMG and nerve conduction testing on site, which allows diagnosis and testing to be coordinated in one place.

Learn more about our neurology services, or visit our contact page for directions to our Westwood office.

This article is for general education and does not replace advice from your own physician. If you think you are having a medical emergency, call 911.