Neuropathy means nerve damage. Specifically, it refers to any condition where nerves outside the brain and spinal cord become injured or stop working properly, disrupting the signals that travel between your body and your central nervous system. Around 17 million people in the United States alone live with diabetic neuropathy, the most common form, making it one of the top three most disabling neurological conditions in the country.
How Nerve Damage Disrupts Your Body’s Signals
Your peripheral nerves are essentially wiring that carries information in both directions: sensory signals travel up to the brain (this is hot, this hurts, this is where my foot is), while motor signals travel down to your muscles (contract, relax, move). A third set of nerves, autonomic nerves, handles things you don’t consciously control, like heart rate, digestion, and sweating.
When nerves are damaged, the problem isn’t just that signals stop. The injured fibers can start firing on their own, sending pain signals when nothing painful is happening. The nerve cell bodies also change their internal chemistry, becoming more excitable and sensitive. Even uninjured nerves that share territory with damaged ones can start misbehaving, amplifying signals they’d normally transmit quietly. Meanwhile, the spinal cord itself becomes more reactive to incoming signals, a process called central sensitization. The result is a nervous system that’s simultaneously numb to some things and hypersensitive to others.
What Neuropathy Feels Like
Symptoms depend on which type of nerve fibers are affected. Most people experience a combination.
Sensory symptoms are the most recognized: pins and needles, numbness, burning or sharp pain (usually starting in the feet), and reduced ability to feel temperature changes. Some people develop a particularly frustrating symptom where a light touch, like a bedsheet brushing against their skin, registers as pain. Loss of position sense in the feet can make you feel unsteady, as if you’re walking on an uneven surface even on flat ground.
Motor symptoms include muscle cramps, twitching, weakness, and gradual muscle wasting. One telltale sign is foot drop, where the front of your foot drags when you walk because the muscles that lift it have weakened.
Autonomic symptoms are less obvious but can be just as disruptive: abnormal sweating, digestive problems, dizziness when standing up, and changes in heart rate or blood pressure.
Types of Neuropathy
Neuropathy isn’t one condition. It’s an umbrella term, and the type depends on how many nerves are involved and where.
- Peripheral neuropathy is the most common form. It typically affects the longest nerves first, which is why symptoms usually start in the feet and hands (a pattern doctors call “stocking-glove distribution”).
- Autonomic neuropathy targets the nerves controlling involuntary functions like digestion, bladder control, and blood pressure regulation.
- Focal neuropathy involves damage to a single nerve, often in the hand, head, torso, or leg. Carpal tunnel syndrome is the most common example. Cranial neuropathies can cause double vision, difficulty focusing, or Bell’s palsy (paralysis on one side of the face). Focal neuropathies that aren’t caused by nerve compression often come on suddenly and improve over weeks to months.
What Causes Nerve Damage
Diabetes is the leading cause, responsible for the vast majority of neuropathy cases. Chronically elevated blood sugar damages nerve fibers over time, and the condition can develop so gradually that significant nerve loss occurs before symptoms become noticeable. People with diabetes who take metformin face an additional risk: the medication can interfere with vitamin B12 absorption in the gut, and B12 deficiency itself causes nerve damage, including demyelination (loss of the protective insulation around nerve fibers).
Beyond diabetes, the list of causes is long. Chemotherapy drugs are a major source, with certain agents directly toxic to nerve fibers. Alcohol abuse damages nerves both through direct toxicity and by causing nutritional deficiencies. Autoimmune conditions like lupus, rheumatoid arthritis, and Guillain-Barré syndrome can trigger the immune system to attack nerve tissue. Infections including HIV and shingles are well-known culprits. Vitamin deficiencies, particularly B12, B6, and folate, impair the nerve’s ability to maintain its structure. Kidney disease, thyroid disorders, and physical injuries round out the common causes. In roughly 30% of cases, no identifiable cause is found, a frustrating category called idiopathic neuropathy.
How Neuropathy Is Diagnosed
Diagnosis usually starts with a clinical exam: checking reflexes, testing sensation with a tuning fork or thin filament, and assessing muscle strength. If neuropathy is suspected, electrodiagnostic testing is the standard next step. This involves two parts: nerve conduction studies, which measure how fast electrical signals travel through your nerves, and needle electromyography (EMG), which assesses how your muscles respond. A thin needle is inserted into the muscle to check for abnormal electrical activity at rest and during contraction. Certain patterns, like spontaneous firing when the muscle should be quiet, indicate the nerve supplying that muscle has been damaged.
These tests have a significant limitation: they can only detect damage to large nerve fibers. Small fiber neuropathy, which causes burning pain and temperature sensitivity, won’t show up on standard electrodiagnostic testing. If your symptoms point to small fiber involvement but your nerve conduction studies come back normal, a skin biopsy can confirm the diagnosis by measuring the density of small nerve endings in a tiny sample of skin.
Blood work typically accompanies these tests to identify underlying causes: blood sugar and hemoglobin A1c for diabetes, B12 levels, thyroid function, kidney markers, and sometimes antibody panels for autoimmune conditions.
Treatment and Pain Management
Treating neuropathy means addressing both the underlying cause and the symptoms. If diabetes is driving the damage, tighter blood sugar control can slow progression. If a vitamin deficiency is responsible, supplementation can sometimes reverse symptoms. Stopping a toxic medication or reducing alcohol intake removes the source of injury.
For neuropathic pain, three categories of medication are considered first-line options. Gabapentinoids work by reducing abnormal nerve signaling. Certain antidepressants that act on both serotonin and norepinephrine are effective for nerve pain independent of their mood effects, and tend to be well tolerated. Older tricyclic antidepressants also help but carry more side effects. The American Academy of Neurology specifically recommends against opioids for diabetic neuropathy pain, a guideline reaffirmed in early 2025.
Non-drug approaches play an important role. Physical therapy helps maintain strength and balance, which is critical given the fall risk that comes with impaired sensation. TENS units, small portable devices that deliver mild electrical currents through skin patches, can reduce localized pain and are inexpensive enough for home use. Cognitive behavioral therapy and related psychological approaches help people manage chronic pain by changing how the brain processes and responds to pain signals. For severe cases that don’t respond to other treatments, spinal cord stimulation, where small electrodes are implanted near the spinal cord, can interrupt pain signaling.
What Happens if Neuropathy Goes Untreated
The most dangerous consequence of untreated neuropathy is losing protective sensation. When you can’t feel pain in your feet, small injuries go unnoticed. A blister, a cut from walking barefoot, or pressure from ill-fitting shoes can progress into an open wound without you ever realizing it. Foot ulcers affect up to one-third of people with diabetes and are the leading cause of non-traumatic lower limb amputations worldwide. People with diabetes face a 10 to 20 times higher risk of amputation compared to the general population.
Wound healing is also compromised in neuropathy, particularly when diabetes is involved. Chronic inflammation, poor blood vessel formation, and impaired tissue repair mean that once a wound develops, it heals slowly or not at all. Ulcers that haven’t reduced by at least half within four weeks are a red flag for inadequate blood flow. The stakes are high: five-year mortality rates after a major lower limb amputation exceed 50% in people with diabetes. This is why daily foot inspections, proper footwear, and regular check-ups are not optional for anyone living with peripheral neuropathy.