Peripheral neuropathy is damage to the nerves outside your brain and spinal cord, typically affecting your hands and feet first. It causes symptoms ranging from tingling and numbness to sharp pain, muscle weakness, and problems with digestion or blood pressure. Around 40% of people with type 2 diabetes develop it, making diabetes the single most common cause, but dozens of other conditions, medications, and deficiencies can trigger it too.
How Nerve Damage Happens
Your peripheral nerves are long cables that carry signals between your brain and the rest of your body. Each nerve fiber has two vulnerable parts: the inner core (the axon) that transmits electrical signals, and an outer insulating layer (the myelin sheath) that helps those signals travel quickly. Peripheral neuropathy can damage either one or both.
In the most common pattern, a metabolic problem like chronically high blood sugar disrupts the nerve’s ability to maintain itself. The farthest ends of the longest nerve fibers break down first because they’re the hardest for the body to supply with nutrients and energy. This is why symptoms almost always start in the toes and feet before working upward. In other cases, the immune system mistakenly attacks the insulating sheath around the nerve, slowing or blocking signal transmission and causing widespread weakness and sensory loss.
Types of Nerves Affected
Your peripheral nervous system contains three types of nerves, and the symptoms you experience depend on which type is damaged. Many people have a mix.
Sensory Nerves
Sensory nerve damage is the most recognized form. It can cause pins and needles, burning or sharp pain (especially in the feet), numbness, and reduced ability to feel temperature changes or pain. Some people develop pain from things that shouldn’t hurt at all, like the light pressure of a bedsheet. Others lose their sense of balance because their brain can no longer tell where their feet are positioned.
Motor Nerves
When motor nerves are involved, you may notice muscle weakness, cramping, twitching, or visible thinning of muscles over time. A characteristic sign is foot drop, where the front of your foot drags when you walk because you can’t lift it properly.
Autonomic Nerves
Autonomic neuropathy affects the nerves that control involuntary body functions. Symptoms are easy to overlook or attribute to something else: constipation or diarrhea (often worse at night), dizziness when standing up due to blood pressure drops, excessive sweating or an inability to sweat, rapid heart rate, bladder problems, and erectile dysfunction. These symptoms can appear alongside sensory or motor problems or on their own.
Common Causes
Diabetes accounts for the largest share of cases. In one large registry study, 42% of people with type 2 diabetes and 29% of those with type 1 had peripheral neuropathy. Prolonged high blood sugar gradually poisons nerve fibers, and the risk climbs the longer blood sugar stays poorly controlled.
Beyond diabetes, the list of causes is long:
- Vitamin deficiencies. Vitamin B12 is essential for nerve health. Serum levels below 200 pg/mL raise concern, and levels below 150 pg/mL are considered diagnostic for deficiency. This is especially common in older adults, strict vegans, and people taking certain acid-reducing medications long term.
- Chemotherapy. Certain cancer drugs are particularly likely to cause nerve damage, including platinum-based drugs (cisplatin, oxaliplatin), taxanes (paclitaxel, docetaxel), and vinca alkaloids (vincristine). Nearly half of people who develop chemotherapy-induced neuropathy still have moderate-to-severe symptoms long after treatment ends.
- Alcohol. Heavy, long-term alcohol use damages nerves both directly and by causing nutritional deficiencies.
- Autoimmune conditions. Disorders like lupus, rheumatoid arthritis, and Guillain-Barré syndrome can trigger immune attacks on peripheral nerves.
- Infections. Shingles, HIV, Lyme disease, and hepatitis C can all cause neuropathy.
- Inherited conditions. Charcot-Marie-Tooth disease is the most common inherited form.
In roughly 20 to 30% of cases, no identifiable cause is found. This is called idiopathic neuropathy, and it’s frustrating but not unusual.
How It’s Diagnosed
Diagnosis typically starts with a physical exam where your doctor tests reflexes, sensation, and muscle strength, often using simple tools like a tuning fork or a thin filament pressed against the sole of your foot. If neuropathy is suspected, a few tests can confirm it and help identify the cause.
Nerve conduction studies and electromyography (EMG) are the standard workup. Nerve conduction studies measure how fast electrical signals travel through your nerves and how well they’re conducted. EMG measures electrical activity in your muscles at rest and during contraction. Together, they reveal whether the problem is in the nerve, the muscle, or the insulating sheath. These tests involve small electrical pulses and thin needle electrodes, which can be uncomfortable but are generally well tolerated.
One limitation is that standard nerve conduction studies only detect damage to larger nerve fibers. If your main symptoms are burning pain and temperature sensitivity, you may have small fiber neuropathy, which requires a different test. A skin biopsy, taken as a tiny punch sample from the lower leg under local anesthesia, allows a lab to count the small nerve fibers in your skin and compare them to normal values. The procedure is quick, doesn’t need stitches, and can be done in a regular office visit.
Blood tests are also part of the workup, checking for diabetes, vitamin deficiencies, thyroid problems, kidney function, and markers of autoimmune disease.
Treatment for Nerve Pain
The first priority is always treating the underlying cause. If diabetes is driving the neuropathy, tighter blood sugar control can slow progression and sometimes improve symptoms. If a vitamin deficiency is responsible, supplementation can partially or fully reverse the damage, especially when caught early. If a medication is the culprit, switching drugs may help.
For pain management, international guidelines recommend starting with one of four medications: duloxetine (an antidepressant that also dampens pain signals), pregabalin or gabapentin (which calm overactive nerve signaling), or amitriptyline (an older antidepressant with pain-relieving properties). A major clinical trial called OPTION-DM found that all four work about equally well. When a single medication at its maximum tolerated dose isn’t enough, combining two of these drugs often provides additional relief.
These medications don’t fix the nerve damage. They reduce pain signals so daily life becomes more manageable. Side effects like drowsiness, dizziness, and weight gain are common, so finding the right medication and dose can take some trial and error.
Non-Drug Approaches
Transcutaneous electrical nerve stimulation (TENS), which delivers mild electrical impulses through pads placed on your skin, has moderate evidence supporting its use for painful diabetic neuropathy. The American Academy of Neurology rates it as “probably effective” for this specific type, based on studies showing modest pain reduction compared to sham devices. It’s low-risk and available over the counter, which makes it a reasonable option to try alongside other treatments.
Physical therapy plays an important role, particularly when motor nerves are affected. Strengthening exercises, balance training, and gait work can reduce fall risk, which is a real concern since neuropathy in the feet makes it harder to sense uneven ground or a misstep. Occupational therapy can help with fine motor tasks if hand numbness or weakness makes daily activities difficult.
For autonomic symptoms, practical adjustments often matter more than medication. Compression stockings and rising slowly from a seated position can help with blood pressure drops. Dietary changes can ease digestive symptoms. Cooling products or moisture-wicking clothing can help manage sweating issues.
What to Expect Over Time
The trajectory of peripheral neuropathy depends heavily on the cause. Neuropathy from a correctable deficiency or a temporary exposure (like a course of chemotherapy) can stabilize or improve once the trigger is removed, though recovery of nerve function is slow, often taking months to years. Nerves regrow at roughly an inch per month, so the longer the affected nerve, the longer the wait.
Diabetic neuropathy tends to be progressive if blood sugar remains uncontrolled, but aggressive management can significantly slow the decline. In some cases, especially when caught early, symptoms plateau or even improve. Idiopathic neuropathy generally progresses slowly and, for many people, remains manageable with symptom control.
The biggest practical risks are ones people don’t always anticipate. Numbness in the feet means you can miss small injuries, blisters, or infections that worsen quickly, particularly if you also have diabetes and reduced blood flow. Checking your feet daily and wearing well-fitting shoes becomes genuinely important. Balance problems increase fall risk, especially in older adults, making home safety modifications and regular exercise more than just general wellness advice.