Why Does My Lower Leg Feel Like It’s Burning?

A burning feeling in the lower leg almost always traces back to irritated or damaged nerves, though the reason those nerves are misfiring varies widely. The sensation is carried by a specific class of nerve fibers that encode slow, diffuse, poorly localized pain, which is why burning in the calf or shin can feel maddeningly hard to pinpoint. Peripheral neuropathy from diabetes or other metabolic problems is the single most common explanation, but vascular disease, trapped nerves, infections, medications, and even intense exercise can all trigger the same complaint.

Why Your Brain Reads It as “Burning”

Your body has two main channels for carrying pain signals. One set of nerve fibers delivers sharp, well-localized pain almost instantly, like the jolt when you step on something pointed. A different set, called C-fibers, carries a slower, diffuse signal that the brain interprets as burning, aching, or searing.¹ When something injures or chronically irritates those C-fibers in the lower leg, whether from inside the body or outside it, the result is that persistent hot, burning quality people describe. This is why so many different conditions produce the same sensation: they all converge on the same small nerve fibers doing the signaling.

Peripheral Neuropathy, the Most Common Culprit

Peripheral neuropathy refers to damage to the nerves outside the brain and spinal cord. It is, by a wide margin, the most frequent reason people experience chronic burning in the feet and lower legs. The damage typically starts in the longest nerves first, which is why symptoms begin in the toes and feet and creep upward over time in a pattern clinicians call a “stocking” distribution. People with peripheral neuropathy describe the pain as burning, searing, stabbing, or feeling like walking on needles.²

Diabetes is the leading cause, responsible for a large share of all peripheral neuropathy cases. Chronically elevated blood sugar damages small blood vessels that feed the nerves, slowly starving them. But diabetes is far from the only metabolic trigger. Vitamin B12 deficiency can produce the same burning feet by disrupting the protective myelin coating around nerve fibers. When B12 is low, a key enzyme cannot properly recycle homocysteine to methionine, and the resulting loss of methylation degrades myelin in both the central and peripheral nervous systems.³ Alcohol misuse, thyroid disorders, and kidney disease round out the list of common metabolic causes. In each case, the burning sensation is a downstream effect of the nerve fibers themselves being slowly destroyed or stripped of insulation.

One frustrating aspect of peripheral neuropathy is that some people develop it without any identifiable cause at all. This idiopathic form accounts for a meaningful fraction of cases and tends to be diagnosed only after doctors rule out every metabolic, toxic, and autoimmune explanation they can think of.

When the Problem Is Blood Flow, Not Nerves

Poor circulation in the legs can mimic or overlap with neuropathic burning, and the two often coexist. Peripheral arterial disease, where plaque narrows the arteries supplying the legs, classically causes cramping during walking that eases with rest. But as the disease progresses to more severe stages, the pain shifts character. In patients with critical limb ischemia, the advanced form of PAD, the pain becomes more burning, stabbing, and constant rather than exercise-related, suggesting the ischemia itself has started damaging nerves.⁴ That shift from a cramping, muscular pain to a neuropathic burning quality is an important red flag that the disease has worsened significantly.

Venous insufficiency, a separate circulatory problem, can also cause burning and discomfort in the lower legs. Here the issue is blood pooling in the veins rather than failing to arrive through the arteries. Venous insufficiency results from venous hypertension caused by structural or functional problems in the veins, often because valves that should push blood upward toward the heart stop working properly.⁵ Symptoms tend to include a heavy, tight, swollen feeling in the legs that worsens after prolonged standing or sitting.⁶ Some people also report a warm or burning sensation, especially around the ankles and lower calves where the pooling is worst. Visible varicose veins, skin discoloration, or swelling that worsens by the end of the day are the telltale clues that point toward a venous rather than a neurological source.

Trapped or Compressed Nerves in the Leg

A nerve does not have to be systemically damaged to cause burning. Sometimes a single nerve gets pinched or compressed at a specific spot, producing localized symptoms. The peroneal nerve, which wraps around the bony knob just below the outside of the knee, is the most commonly compressed nerve in the lower leg. Its superficial branch is most often entrapped as it exits the lateral compartment of the leg, and compression can cause burning, tingling, or numbness along the outer shin and top of the foot.⁷ Habitual leg-crossing, prolonged squatting, tight boots, and even a leg cast can trigger it.

Farther down the leg, tarsal tunnel syndrome involves compression of the tibial nerve or one of its branches as it passes through a narrow channel on the inner side of the ankle. The result is numbness, burning, and tingling on the sole of the foot, the heel, or the inner ankle.⁸ Think of it as the leg’s equivalent of carpal tunnel syndrome in the wrist. These entrapment neuropathies differ from widespread peripheral neuropathy in that the burning stays confined to the territory of one nerve, which helps doctors figure out where the compression is happening.

Medications and Toxins That Damage Leg Nerves

Chemotherapy is one of the most well-known pharmaceutical causes of burning pain in the feet and lower legs. The neuropathy it produces affects a large proportion of patients receiving treatment. Depending on the drug used, the result can be a pure sensory neuropathy producing pain and burning, or a mixed sensorimotor neuropathy that also weakens muscles.⁹ Platinum-based drugs like cisplatin tend to produce mainly sensory symptoms, while drugs like vincristine can also affect motor and autonomic nerves.

Among chemotherapy agents, paclitaxel is particularly notorious. It induces neuropathy in a very high proportion of patients treated for gynecological and urological cancers, with some studies reporting rates as high as 97%. The drug accumulates in the nerve cell bodies near the spine, causing the longest axons to degenerate from their tips backward, which is why numbness and burning start in the feet.¹⁰ The symptoms sometimes persist long after chemotherapy ends, which can come as an unwelcome surprise to patients who assumed the burning would resolve once treatment stopped.

Beyond chemotherapy, other medications and toxins can produce similar nerve damage. Certain antibiotics, anti-seizure drugs, and antiretroviral medications for HIV carry neuropathy risk. Chronic alcohol use damages nerves both through direct toxicity and by depleting B vitamins needed for nerve maintenance. Industrial chemical exposure, particularly to heavy metals, is a rarer but real cause. If burning in your lower legs appeared or worsened after starting a new medication, that timing is worth mentioning to your doctor.

Small Fiber Neuropathy, the Under-the-Radar Diagnosis

This is where things get frustrating for many patients. Standard nerve conduction studies, the electrical tests doctors typically order when they suspect neuropathy, only detect damage to large nerve fibers. Small fibers, the very C-fibers responsible for burning pain, do not show up on those tests. A person can have significant small fiber damage and a completely normal nerve conduction study. In one prospective evaluation, over a third of patients with painful sensory neuropathy had normal electrical studies but reduced small fiber density when tested by skin biopsy.¹¹

This means that if your burning leg pain led to a nerve conduction test that came back “normal,” it does not necessarily mean your nerves are fine. A skin punch biopsy, where a tiny sample is taken from the lower leg and the density of nerve endings in the skin is counted under a microscope, is the definitive way to diagnose small fiber neuropathy. The biopsy is simple, about the size of a pencil eraser, and usually heals without issue.

Some autoimmune conditions, like Sjögren’s syndrome, preferentially damage these small fibers while leaving large fibers intact.¹² This is why a burning lower leg in someone with dry eyes and dry mouth, the hallmarks of Sjögren’s, should raise suspicion. Other autoimmune and inflammatory conditions, including sarcoidosis and celiac disease, have also been linked to small fiber neuropathy. The practical takeaway: if standard tests are normal but the burning is real, push for a skin biopsy and an autoimmune workup.

Exercise-Induced Burning in the Shin or Calf

If the burning only happens during exercise and goes away within minutes of stopping, chronic exertional compartment syndrome is a strong possibility. The muscles of the lower leg are enclosed in tight fascial compartments, and during vigorous exercise the muscles swell with blood flow. In some people the fascial walls cannot stretch enough to accommodate this, and the rising pressure inside the compartment compresses nerves and blood vessels, producing pain, tightness, and sometimes a burning or numb sensation.¹³ The anterior compartment (front of the shin) is the most commonly affected.

This condition is most often seen in young recreational runners, elite athletes, and military recruits. A defining feature is the predictability: symptoms tend to kick in at roughly the same point in a run or workout every time and resolve within minutes to half an hour of rest.¹⁴ It is frequently misdiagnosed as shin splints. The key difference is that shin splints produce tenderness along the bone itself, while compartment syndrome feels more like a deep pressure or burning within the muscle belly. Diagnosis requires measuring the pressure inside the compartment before and after exercise.

Skin Infections That Mimic Nerve Pain

Not everything that burns in the lower leg is neurological. Cellulitis, a bacterial skin infection, produces pain, redness, warmth, and swelling that can feel remarkably like burning from the inside.¹⁵ The lower leg is a common site for cellulitis because minor cuts, cracks in dry skin, or fungal infections between the toes provide entry points for bacteria. Venous insufficiency and lymphedema increase the risk further by causing fluid to pool in the tissues.

The burning from cellulitis differs from neuropathic burning in a few ways. It typically develops over hours to days rather than weeks or months, the skin over the area is visibly red and hot to the touch, and there is usually swelling. Fever and feeling generally unwell are common. If your lower leg is burning and the skin looks angry, red, and warm, cellulitis needs to be ruled out quickly because it requires antibiotics and can spread rapidly if untreated.

Rarer Conditions That Cause Intense Burning

A handful of less common disorders deserve mention because they produce distinctive burning that can be misattributed to more familiar causes.

Erythromelalgia causes episodes of severe burning, redness, and warmth in the feet and lower legs, typically triggered by heat or physical activity. The episodes can only be relieved by cooling the affected area. The underlying problem appears to involve sensitized C-fiber receptors in the skin whose threshold for activation by heat drops well below normal body temperature, meaning warmth that would be harmless for most people triggers intense pain signals and reflexive blood vessel dilation.¹⁶ People with erythromelalgia often sleep with their feet outside the covers or soak them in cold water for relief. The condition is rare but often goes undiagnosed for years because its episodic nature means it may not be visible during a doctor’s visit.

Complex regional pain syndrome, or CRPS, can develop after an injury to the leg, even a seemingly minor one like a sprain. The hallmarks are intense burning pain, swelling, skin color changes, and temperature differences between the affected and unaffected limbs. Research shows that CRPS involves degeneration of the small nerve fibers responsible for pain and autonomic function, with affected areas showing roughly a 29% reduction in small fiber density compared to normal skin on the same person’s other limb.¹⁷ CRPS is disproportionately painful relative to the original injury, and early recognition matters because treatment is more effective when started early.

Post-herpetic neuralgia, the lingering nerve pain that follows a shingles outbreak, can also produce burning in the lower leg if the rash affected that area. Shingles involves reactivation of the chickenpox virus in a nerve root, and after the rash heals, a subset of patients are left with constant deep, burning pain, along with heightened sensitivity to touch.¹⁸ The risk rises sharply with age, which is one reason the shingles vaccine is recommended for older adults.

When Restless Legs Turn Painful

Most people think of restless legs syndrome as an urge to move the legs, not a pain condition. But a subset of people with RLS experience a distinctly painful form, and when researchers asked those patients to describe the sensation, “burning” was the most frequently chosen word, reported by roughly 37 to 44% of patients with painful RLS.¹⁹ The burning in RLS tends to be worst in the evening and at night, improves with movement, and is accompanied by the characteristic fidgety, crawling discomfort in the legs. If your burning legs are keeping you up at night and the only thing that helps is getting up and walking, painful RLS is worth discussing with your doctor. It responds to different treatments than standard neuropathy.

Sorting Through the Possibilities

Given how many conditions can produce a burning lower leg, a systematic approach to diagnosis matters. A few questions help narrow the field quickly:

• When does it happen? Constant burning suggests neuropathy or vascular disease. Burning that comes only during exercise points to compartment syndrome. Burning triggered by warmth or at night suggests erythromelalgia or RLS.
• Where exactly? Burning in a stocking pattern on both legs is classic for peripheral neuropathy. Burning on the outer shin and top of the foot suggests peroneal nerve compression. Burning on the sole points toward tarsal tunnel syndrome.
• What else is going on? Redness and skin warmth suggest cellulitis or erythromelalgia. Visible varicose veins and heaviness lean toward venous insufficiency. Muscle weakness alongside the burning raises the possibility of a motor neuropathy or nerve entrapment.
• What changed recently? A new medication, a recent injury, sudden weight loss, or a change in alcohol use can all point to the cause.

The diagnostic workup typically starts with blood tests checking blood sugar, B12, thyroid function, kidney function, and markers of inflammation. Nerve conduction studies can detect large fiber neuropathy and localize entrapment. If those are normal, skin biopsy testing for small fiber neuropathy is the next step. For erythromelalgia, a combined neurological and vascular workup including tests of skin blood flow, temperature, and autonomic nerve function helps pin down the diagnosis.²⁰ Vascular studies including ankle-brachial pressure measurements are straightforward and noninvasive for checking arterial blood flow.

One thing worth knowing: many people with burning legs have more than one contributing factor. A person with mild diabetic neuropathy, some venous insufficiency, and a vitamin D deficiency may not have one neat diagnosis. Treating each contributing factor often reduces the burning even when no single treatment eliminates it entirely. The worst strategy is to accept “your nerves are fine” based on a single normal nerve conduction test and stop investigating. If the burning is real, there is almost always a diagnosable explanation.