Nerve pain happens when nerve fibers themselves become damaged, inflamed, or compressed, causing them to misfire and send pain signals even when there’s no injury at the site where you feel the pain. Unlike the sharp sting of a cut or the ache of a bruise, nerve pain originates in the nervous system itself. The causes range from chronic diseases like diabetes to physical injuries, infections, and even certain medications.
How Nerve Pain Differs From Other Pain
Most pain works like an alarm system. You touch something hot, sensory nerves detect the threat, and they send a signal to your brain that registers as pain. Once the tissue heals, the alarm stops. Nerve pain breaks this system. When nerve fibers are injured or diseased, they become hyperexcitable: their threshold for firing drops, they discharge spontaneously, and they produce exaggerated responses to ordinary stimuli. A light touch on the skin can register as burning or stabbing pain, a phenomenon called allodynia.
This process, called peripheral sensitization, is driven by a flood of inflammatory molecules released by immune cells and neighboring nerve endings at the injury site. These molecules alter the sensitivity of receptors and ion channels on nerve fibers, essentially turning up the volume on pain signaling. Over time, the spinal cord and brain themselves can rewire in response, amplifying pain signals even further through a process called central sensitization. This is why nerve pain can persist long after the original injury has resolved, and why it often feels so different from a pulled muscle or a broken bone.
Diabetes: The Most Common Cause
More than half of all people with diabetes develop some form of nerve damage. This makes diabetes the single most common cause of peripheral neuropathy worldwide. The damage typically starts in the longest nerves first, which is why tingling, numbness, and burning pain usually begin in the feet and work upward.
Chronically elevated blood sugar drives nerve damage through several interconnected pathways. High glucose levels cause the energy-producing structures inside cells (mitochondria) to overproduce harmful molecules called free radicals. This oxidative stress triggers a cascade: sugar-derived waste products accumulate in nerve tissue, proteins become abnormally modified, and stress-response pathways activate throughout the cell. The combined effect impairs nerve function, cuts off the growth signals that nerves need to stay healthy, and eventually kills both neurons and the supportive cells that insulate them. Blood vessel damage compounds the problem by reducing blood flow to the nerves themselves, starving them of oxygen and nutrients.
Tight blood sugar control is the most effective way to slow or prevent diabetic nerve damage, particularly in type 1 diabetes. For people with type 2 diabetes, the relationship is less straightforward, but maintaining stable glucose levels remains the cornerstone of prevention.
Physical Compression and Structural Problems
Nerves can be physically squeezed by surrounding structures, and when they are, pain, numbness, or weakness follows. The most familiar example is sciatica, where a herniated disc in the lower spine presses on the sciatic nerve and sends shooting pain down the leg. But compression can happen anywhere along a nerve’s path.
In the spine, several age-related changes narrow the space available for nerves. Bone spurs from arthritis can push into the spinal canal. The soft cushions between vertebrae (discs) can bulge or rupture, pressing directly on nerve roots. The ligaments that hold the spine together can thicken and stiffen over time, further crowding the canal. This condition, spinal stenosis, is one of the most common structural causes of nerve pain in older adults.
Outside the spine, nerves can become trapped where they pass through tight anatomical tunnels. Carpal tunnel syndrome compresses the median nerve at the wrist. Cubital tunnel syndrome pinches the ulnar nerve at the elbow, producing the “funny bone” sensation in a more persistent form. Repetitive motions, prolonged pressure, or swelling from injury or inflammation can all trigger these entrapment syndromes.
Infections That Damage Nerves
Several infections can injure nerve fibers directly or trigger an immune response that damages them as collateral. Shingles is one of the most well-known examples. The varicella-zoster virus, the same virus that causes chickenpox, remains dormant in sensory nerve clusters for decades after the initial infection. When it reactivates, it travels back along nerve fibers to the skin, causing a painful blistering rash.
The real problem for many people comes after the rash heals. Postherpetic neuralgia, the nerve pain that lingers after shingles, stems from damage to both peripheral and central nerve fibers caused by the immune and inflammatory response during viral reactivation. Damaged nerve fibers develop a lower firing threshold and begin discharging on their own, producing burning or stabbing pain in the area where the rash appeared. This pain can last months or even years.
HIV can also cause peripheral neuropathy, both from the virus itself and from some of the medications used to treat it. Lyme disease, hepatitis C, and certain other infections are additional triggers, each damaging nerves through slightly different mechanisms involving direct viral or bacterial injury, inflammation, or immune-mediated attack.
Autoimmune Diseases
When the immune system mistakenly attacks the body’s own nerve tissue, the result is often painful and difficult to diagnose. Several autoimmune and inflammatory conditions are strongly linked to nerve damage.
Sjögren syndrome, best known for causing dry eyes and dry mouth, produces peripheral neuropathy in up to 60% of patients. Systemic vasculitis, which inflames blood vessels, causes nerve damage in up to 70% of affected individuals by destroying the small arteries that supply blood to nerve fibers. Lupus triggers neuropathy in roughly 15% of cases. In these conditions, the damage comes from multiple angles: inflammatory molecules directly poison nerve fibers, autoantibodies attack nerve components, immune cells infiltrate nerve tissue, and inflamed blood vessels cut off the nerve’s blood supply.
Guillain-Barré syndrome is a more acute example. The immune system attacks the insulating sheath around peripheral nerves, causing rapid-onset weakness and sometimes pain that can progress over days to weeks. Unlike the slow neuropathy of Sjögren or lupus, Guillain-Barré is a medical emergency, but the underlying principle is the same: the immune system treats nerve tissue as a threat.
Chemotherapy and Other Medications
Certain medications are directly toxic to nerve fibers, and chemotherapy drugs are the most common culprits. Chemotherapy-induced peripheral neuropathy affects a significant portion of cancer patients and can sometimes persist long after treatment ends.
The drug classes most likely to cause nerve damage include platinum-based compounds (used in lung, breast, ovarian, and colon cancers), taxanes (widely used in breast and ovarian cancer), vinca alkaloids (used in blood cancers and lymphomas), and drugs like bortezomib, which causes neuropathy in 37% to 44% of people treated for multiple myeloma. Thalidomide, used for certain blood cancers, is another frequent offender, though its newer relatives are less neurotoxic.
Outside of cancer treatment, other medications can contribute. High-dose or prolonged courses of certain antibiotics (particularly fluoroquinolones and metronidazole), some heart medications, and antiretroviral drugs used to treat HIV have all been associated with nerve damage. If you’re experiencing new tingling, numbness, or pain during any medication regimen, it’s worth raising with your prescriber, since early recognition sometimes allows a switch to a less neurotoxic alternative.
Nutritional Deficiencies
Your nerves depend on specific vitamins to maintain their structure and function, and deficiencies can cause or worsen neuropathy. Vitamin B12 plays a confirmed role in nerve health. Deficiency is especially common in older adults, people who follow strict vegan diets, and those taking long-term acid-reducing medications, which impair B12 absorption. The resulting neuropathy typically causes numbness and tingling in the hands and feet, and it can sometimes be reversed if caught early.
Vitamin B6 has a more complicated relationship with nerve pain. Low levels are sometimes found in people with neuropathy, but research has not firmly established that B6 deficiency directly causes nerve damage on its own. Paradoxically, too much B6 is a clearer problem. Supplementing above 100 mg per day (the FDA’s upper limit) can itself trigger peripheral neuropathy, and the recommended daily intake is only 1.6 to 2 mg. This makes B6 one of the few vitamins where both too little and too much may contribute to nerve symptoms.
Alcohol and Other Toxins
Chronic heavy drinking is one of the more common causes of neuropathy outside of diabetes. Alcohol damages nerve fibers both directly, through its toxic effects on nerve cells, and indirectly, by impairing the absorption of B vitamins and other nutrients essential for nerve maintenance. The neuropathy typically develops gradually, starting with burning or prickling sensations in the feet and lower legs.
Industrial and environmental toxins can also cause nerve damage. Lead, mercury, arsenic, and certain organic solvents are all neurotoxic with sufficient exposure. These causes are less common in the general population but remain relevant for people with occupational exposures or contaminated water sources.
How Nerve Pain Is Identified
Nerve pain can be tricky to pin down because it often coexists with other types of pain, and there’s no single test that definitively diagnoses it. Doctors typically start with your description of the pain itself. Burning, shooting, electric shock sensations, tingling, and pain triggered by light touch are all hallmarks that point toward a nerve origin rather than a muscle or joint problem.
Standardized screening questionnaires help clinicians distinguish nerve pain from other types. These short assessments ask about specific sensations and perform simple bedside tests, like checking whether light brushing of the skin triggers pain. The most widely validated tools show strong accuracy, with sensitivity (ability to detect nerve pain when it’s present) reaching 87% and specificity (ability to rule it out when it’s absent) reaching 85%.
From there, the diagnostic path depends on the suspected cause. Blood tests can identify diabetes, vitamin deficiencies, or autoimmune markers. Nerve conduction studies measure how quickly electrical signals travel through your nerves, revealing areas of damage or slowed transmission. Imaging like MRI can identify structural compression from herniated discs or spinal stenosis. In some cases, a small skin biopsy can confirm damage to the tiny nerve fibers in the skin, which is particularly useful for diagnosing small fiber neuropathy that other tests miss.