An internal burning sensation can arise from dozens of different conditions, ranging from stomach acid washing into your esophagus to tiny nerve fibers in your skin slowly dying off. The feeling is real, not imagined, and it traces back to a specific set of sensory receptors and neural pathways that your body uses to signal tissue damage or irritation. What makes the symptom confusing is that the same “burning” quality can originate in your gut, your peripheral nerves, your spinal cord, or even your brain’s own pain-processing centers, and sorting out which one is driving the sensation is the key to getting relief.
How Your Body Creates the Sensation of Burning
Your nervous system has a dedicated molecular alarm for heat and chemical irritation: a receptor called TRPV1, found on pain-sensing nerve fibers throughout your body. This receptor responds to actual heat, to acids, and to chemicals like capsaicin (the compound that makes chili peppers hot). When activated, it triggers the same C-fiber and A-delta nerve fibers that fire when you touch a hot stove, producing a burning sensation even when no external heat is present.1PubMed. The role of TRPV1 receptors in pain evoked by noxious thermal and chemical stimuli In healthy tissue, TRPV1 acts as a first line of defense against heat injury.2PubMed Central. The capsaicin receptor TRPV1 is the first line defense protecting from acute non damaging heat: a translational approach
The problem is that inflammation, nerve damage, and chemical exposure can all make these receptors hypersensitive or cause them to fire spontaneously. When that happens, you feel burning without any heat source. Understanding this helps explain why so many unrelated conditions share that same unpleasant quality: they all ultimately converge on the same pain-sensing hardware.
Acid Reflux and Gastric Burning
The most familiar kind of internal burning is heartburn, which has nothing to do with your heart. When stomach acid escapes upward through a weakened lower esophageal sphincter, it contacts the lining of the esophagus, which lacks the thick mucus barrier that protects the stomach itself. Acid-sensitive nerve fibers running through both vagal and spinal pathways pick up the irritation and translate it into a burning sensation behind your breastbone or in the upper abdomen.3PubMed. Roles of gastro-oesophageal afferents in the mechanisms and symptoms of reflux disease Repeated acid exposure can actually change the sensitivity of those nerve fibers, making them fire more readily over time. This is why chronic reflux often feels worse as months or years pass, even when the amount of acid hasn’t changed.
It is worth noting that not all upper-abdominal burning points to reflux. Some people develop a burning sensation from gastritis or functional dyspepsia where the stomach lining itself is irritated but acid isn’t escaping upward. One endoscopy study found that common symptoms like epigastric pain, heartburn, and bloating didn’t reliably correlate with how severe the gastritis actually was under the microscope, which means the intensity of your burning feeling isn’t a reliable guide to what’s happening at the tissue level.4PubMed Central. Symptoms, gastritis, and Helicobacter pylori in patients referred for endoscopy That disconnect is one reason doctors often want to look directly at the esophagus and stomach with a scope rather than guess based on symptoms alone.
Small Fiber Neuropathy and Burning Feet
If your burning sensation is in your hands or feet rather than your torso, nerve damage is a prime suspect. Small fiber neuropathy is increasingly recognized as a major cause of painful burning in the feet, particularly as people age. The small-diameter nerve fibers closest to the skin surface, the same C and A-delta fibers that carry temperature and pain signals, become damaged or die back. The result is spontaneous burning, tingling, and prickling that tends to start in the toes and creep upward over time.5PubMed Central. Small fiber neuropathy: A burning problem
Diabetes is the most common identifiable cause. High blood sugar and abnormal blood fats damage nerve fibers directly. Biopsy studies of peripheral nerves in people with early diabetic neuropathy show damage to C and A-delta fibers even before the larger motor nerves are affected, which explains why burning pain can appear years before any weakness or loss of coordination.6PubMed. Diabetic peripheral neuropathy essentials: a narrative review Even prediabetes, impaired glucose tolerance that doesn’t yet meet the threshold for a diabetes diagnosis, has been linked to small fiber damage. If you have unexplained burning in your feet and no one has checked your blood sugar or done an oral glucose tolerance test, that’s a reasonable first step.
Vitamin deficiencies can also destroy peripheral nerve fibers. B12 deficiency is the most widely known culprit, but deficiencies of B1 (thiamine), B6, and other nutrients can produce similar burning neuropathies. Peripheral nerves are vulnerable to a wide range of nutritional shortfalls and toxic exposures, and the resulting nerve damage often shows up as a burning or tingling pain that starts at the extremities and works inward.7PubMed Central. Peripheral neuropathy due to vitamin deficiency, toxins, and medications
Alcohol and Toxic Exposures
Long-term heavy drinking is another well-established cause of burning neuropathy. Alcoholic neuropathy produces spontaneous burning pain along with heightened sensitivity to touch and temperature, a combination that can make even wearing socks feel unbearable. The damage comes from two directions at once: the direct toxic effect of alcohol on nerve tissue and the nutritional deficiencies (especially thiamine) that heavy drinkers frequently develop.8PubMed Central. Alcoholic neuropathy: possible mechanisms and future treatment possibilities Simply supplementing vitamins without reducing alcohol intake usually isn’t enough to reverse the damage, because the alcohol itself is part of the problem.
Workplace chemical exposure is another underappreciated route to burning sensations. Chronic exposure to heavy metals has been studied for its effects on small nerve fibers in industrial workers.9PubMed Central. The impact of chronic co-exposure to different heavy metals on small fibers of peripheral nerves. A study of metal industry workers Certain chemotherapy drugs are notorious for it as well. If burning pain in your hands or feet started within weeks of beginning a new medication or a new job involving chemical exposure, that timing is worth mentioning to your doctor.
Shingles and the Pain That Outlasts the Rash
Shingles provides one of the most dramatic examples of internal burning. The varicella-zoster virus, the same virus that causes chickenpox, can hide dormant in nerve cell clusters for decades and then reactivate. When it does, it causes a painful, blistering rash that typically follows a single band or strip on one side of the body. The rash itself heals within about two to four weeks in most cases.10ScienceDirect. Herpes Zoster and Postherpetic Neuralgia But in some people, the virus inflicts enough nerve damage that the burning pain persists long after the skin has healed.
This lingering pain, called postherpetic neuralgia, can include a constant deep burning, sudden shooting pains, and painful reactions to stimuli that shouldn’t hurt, like the brush of clothing against skin.11PubMed. Post-herpetic Neuralgia: a Review The burning quality is especially characteristic. It can persist for months or years and is one of the more difficult chronic pain conditions to treat. The risk is highest in older adults and people with weakened immune systems, which is part of why the shingles vaccine is recommended for adults over 50.
Autoimmune Conditions That Attack Nerves
Several autoimmune diseases can target the small nerve fibers responsible for burning pain. Sjögren syndrome, best known for causing dry eyes and dry mouth, is a notable example. Some Sjögren patients develop severe neuropathic pain with a distinctive burning or lancinating quality. What makes it unusual is that the small fiber damage doesn’t always follow the typical foot-to-hand pattern seen in diabetes. It can disproportionately affect the torso, the face, or scattered patches of skin in what researchers call a non-length-dependent distribution.12PubMed Central. Peripheral nervous system manifestations of Sjögren syndrome: clinical patterns, diagnostic paradigms, etiopathogenesis, and therapeutic strategies If you have burning pain that appears in odd locations rather than the expected hands-and-feet pattern, an autoimmune workup may be warranted.
Other autoimmune and inflammatory conditions, including lupus, sarcoidosis, and celiac disease, have also been associated with small fiber neuropathy. The mechanism differs from condition to condition, but the end result is similar: the immune system damages sensory nerve fibers, and burning pain results.
When the Spinal Cord and Brain Amplify Pain
Sometimes the burning sensation doesn’t start in a damaged nerve or an irritated organ. Instead, the central nervous system itself becomes the problem. In a process called central sensitization, the spinal cord and brain’s pain-processing circuits become hyperexcitable. Neurons that relay pain signals start responding more intensely to normal inputs or fire without any peripheral input at all. Sustained increases in inflammatory signaling molecules within the central nervous system can promote chronic widespread pain that affects multiple body regions simultaneously.13PubMed Central. Neuroinflammation and Central Sensitization in Chronic and Widespread Pain
Fibromyalgia is the condition most associated with this phenomenon. Neurophysiologic testing in fibromyalgia patients has provided strong evidence for a state of central hyperexcitability in the pain system, meaning the volume knob on pain perception is turned up even when the peripheral nerves are intact.14PubMed. Neurophysiologic evidence for a central sensitization in patients with fibromyalgia Burning skin, aching muscles, and sensitivity to light touch are common complaints in fibromyalgia, and they reflect what is happening in the spinal cord and brain rather than local tissue damage. This is important to grasp, because it means normal imaging and blood work can all come back clean while the pain is very real.
Burning Mouth Syndrome
A particularly frustrating variant of internal burning targets the mouth. Burning mouth syndrome produces a scalding, tingling, or hot sensation, most often on the front two-thirds and the tip of the tongue, though the palate, gums, and inner cheeks can also be affected. The mouth looks completely normal, and routine lab tests come back unremarkable, which makes it a diagnosis of exclusion. It disproportionately affects postmenopausal women, suggesting a hormonal connection, though no single definitive cause has been identified.15PubMed Central. Burning mouth syndrome and menopause
The pain tends to be absent or mild in the morning and ramp up through the day, reaching its worst by evening. Dry mouth, altered taste, and anxiety frequently accompany it. Because there is no visible lesion and no clear-cut lab marker, people with burning mouth syndrome are sometimes told nothing is wrong. That dismissal can be deeply frustrating. The condition appears to involve some combination of small fiber nerve changes in the oral mucosa and altered central pain processing, putting it in the same broad family as the neuropathic and central sensitization conditions described above.
How Doctors Track Down the Source
Given how many different conditions can cause an internal burning feeling, diagnosis often involves working through a systematic checklist. Where the burning is located, when it started, what makes it better or worse, and what other symptoms accompany it all narrow the possibilities.
For burning in the chest or upper abdomen, a trial of acid-suppressing medication is often the first diagnostic step. If the burning resolves, reflux was likely the cause. If it doesn’t, an endoscopy may follow. For burning in the extremities, blood glucose testing, a metabolic panel, and vitamin levels (B12, folate, thiamine) are standard starting points. Nerve conduction studies can evaluate the large nerve fibers, but small fiber neuropathy requires different tools because the damaged fibers are too small to show up on standard electrical tests.
Skin biopsy has become the gold-standard method for confirming small fiber neuropathy. A small punch of skin, usually taken from the lower leg, is examined under a microscope to count the density of nerve endings in the outer layer of skin. A reduced density confirms that small fibers have been lost.16PubMed Central. Investigation of nerve fibers in the skin by biopsy: technical aspects, indications, and contribution to diagnosis of small-fiber neuropathy In one large patient cohort, about 40% of those suspected of having small fiber neuropathy showed reduced nerve fiber density on biopsy, and about half had abnormalities on quantitative sensory testing, which measures how well you can detect warm and cold stimuli on the skin.17PubMed. The value of skin biopsy with recording of intraepidermal nerve fiber density and quantitative sensory testing in the assessment of small fiber involvement in patients with different causes of polyneuropathy Neither test alone catches every case, so doctors sometimes use both together.
When burning pain is widespread and no peripheral nerve damage is found, the focus shifts to central sensitization and conditions like fibromyalgia. Autoimmune blood panels (looking for markers of Sjögren syndrome, lupus, and related conditions) are also worth running, because autoimmune-driven nerve damage can be subtle and easy to miss.
Treatments That Target the Burning
Treatment depends entirely on the cause, which is why diagnosis matters so much. Acid reflux responds to proton pump inhibitors and lifestyle changes. Diabetic neuropathy requires blood sugar management as the foundation, since continued hyperglycemia drives further nerve damage. Vitamin deficiencies need supplementation, and toxic exposures need to be removed.
For neuropathic burning pain itself, regardless of the underlying cause, a handful of medications have strong evidence of benefit. Gabapentin and pregabalin work by binding to a specific site on voltage-gated calcium channels in the nervous system, dampening the overexcited nerve signals that produce burning pain. Duloxetine takes a different approach, boosting serotonin and norepinephrine in the spinal cord’s descending pain-control pathways.18PubMed Central. Evaluation of efficacy and safety of gabapentin, duloxetine, and pregabalin in patients with painful diabetic peripheral neuropathy All three are used as first-line treatments for diabetic neuropathy and are frequently tried for other neuropathic burning conditions as well.
Topical treatments can be surprisingly effective for localized burning. High-concentration capsaicin patches apply the same compound that activates TRPV1 receptors, but in a way that initially overstimulates and then temporarily desensitizes the local pain nerves.19PubMed Central. Capsaicinoids in the treatment of neuropathic pain: a review A single 60-minute application of a high-concentration patch can reduce nerve fiber activity in the treated skin for weeks or months, providing a window of relief without systemic side effects.20British Journal of Anaesthesia. Topical capsaicin for pain management: therapeutic potential and mechanisms of action of the new high-concentration capsaicin 8% patch The irony isn’t lost on patients: the same molecule that causes burning is used to treat it.
For severe, medication-resistant burning pain, especially in conditions like complex regional pain syndrome, spinal cord stimulation is an option. A small device delivers mild electrical pulses to the spinal cord, interrupting the pain signals before they reach the brain. In one prospective study of patients with complex regional pain syndrome and severe disability, spinal cord stimulation reduced both deep pain and surface sensitivity from the maximum on a standard pain scale down to near zero.21PubMed. Spinal cord stimulation in sympathetically maintained complex regional pain syndrome type I with severe disability. A prospective clinical study It isn’t appropriate for every type of burning pain, but for the right patient it can be transformative.
Why Burning Pain Gets Dismissed and What to Do About It
One of the more common frustrations people with internal burning sensations face is being told that nothing is wrong. Standard blood work, imaging, and nerve conduction studies can all return normal results while the pain continues unabated. This happens because many burning-pain conditions involve the smallest nerve fibers or central processing changes that standard tests simply don’t measure. A normal MRI doesn’t rule out small fiber neuropathy. A normal nerve conduction study doesn’t rule it out either. A normal endoscopy doesn’t rule out functional dyspepsia or esophageal hypersensitivity.
If you’re in this situation, a few things are worth knowing. First, ask specifically about small fiber neuropathy testing, including skin biopsy, if your burning is in the extremities and standard nerve tests came back normal. Second, if your burning is widespread and accompanied by fatigue, sleep problems, or sensitivity to pressure, bring up central sensitization and fibromyalgia explicitly. Third, keep a symptom diary noting when the burning is worst, what triggers it, and what relieves it. Patterns often point toward a cause that a single office visit can miss. And fourth, be aware that burning pain from nerve damage or central sensitization is a recognized medical condition with established treatments. “We can’t find a cause” is not the same as “there is no cause.” It usually means the right test hasn’t been ordered yet.
Burning Sensations During Menopause and Hormonal Shifts
Hormonal changes deserve a separate mention because they contribute to burning pain in ways that many people don’t expect. The link between menopause and burning mouth syndrome is the most studied example, but perimenopausal and menopausal women also report burning skin sensations on the scalp, face, and extremities more frequently than the general population. The drop in estrogen appears to affect both nerve fiber health and central pain processing. Estrogen has neuroprotective effects, and its withdrawal may leave small nerve fibers more vulnerable to damage or dysfunction.
This doesn’t mean that burning pain during menopause should simply be chalked up to hormones and left untreated. Other causes, including thyroid disease, diabetes, and autoimmune conditions, all become more common with age and need to be ruled out. But when the standard workup is negative and the timing lines up with hormonal changes, the connection is worth discussing with a clinician who takes it seriously.