A burning sensation in the body is an unpleasant, abnormal sensation that is not caused by an external heat source or thermal injury. The symptom can range from a mild tingling to an intense, painful heat, and its presence often signals an underlying issue involving the nervous system. Understanding the physical mechanisms and various causes is the first step toward finding relief.
When Nerves Misinterpret Signals
The sensation of burning, prickling, or electric shock occurs when the peripheral nervous system malfunctions. These symptoms are generated not by actual heat, but by irritation or damage to the sensory nerves that transmit information to the brain. Sensory nerves contain specialized pain receptors called nociceptors, which are responsible for detecting signals of potential harm.
The small, unmyelinated nerve fibers, known as C-fibers, are particularly important in transmitting the slow, lingering pain often described as burning. When these nerve endings are injured, they can become hyperexcitable, meaning they fire electrical impulses spontaneously or over-react to mild stimuli. This misfiring sends an incorrect, amplified signal along the nerve pathway, which the brain interprets as a sensation of intense heat or pain. This physiological error is the root cause of neuropathic pain.
Systemic Diseases and Metabolic Imbalances
The most frequent cause of chronic, widespread burning sensations is peripheral neuropathy, which is nerve damage resulting from a systemic disease. Diabetes is the leading cause, where high blood glucose levels damage the small blood vessels supplying oxygen and nutrients to the nerve fibers over many years. This diabetic neuropathy typically begins with a burning or tingling sensation in the feet and toes, following a “stocking” distribution that climbs up the legs as the damage progresses.
Other chronic conditions that disrupt the body’s chemistry can also poison or starve the nerves. Advanced kidney disease allows toxins to build up in the bloodstream, which can damage nerve tissue. Similarly, chronic liver disorders impair metabolism, leading to a buildup of neurotoxic compounds that initiate nerve injury.
The endocrine system also plays a regulatory role in nerve health, and an underactive thyroid gland can cause fluid retention that compresses nerves and leads to neuropathy. Furthermore, deficiencies in certain micronutrients are a direct cause of nerve damage. A lack of Vitamin B12 and folate is particularly implicated, as these vitamins are essential for the production and maintenance of the nerve’s protective myelin sheath.
Localized Nerve Compression and Skin Conditions
Nerve entrapment syndromes occur when a specific peripheral nerve is physically compressed or squeezed as it passes through a narrow anatomical space. Carpal Tunnel Syndrome is a common example where the median nerve in the wrist is compressed, causing burning, numbness, and tingling primarily in the hand and fingers.
Another frequent localized cause is Meralgia Paresthetica, where the lateral femoral cutaneous nerve becomes trapped near the hip, resulting in burning pain on the outer side of the thigh. An acute viral infection can also inflame nerve pathways, most notably the Herpes Zoster virus, which causes Shingles. This virus reactivates in the sensory nerves and produces a painful, intensely burning rash that follows the path of the infected nerve.
Beyond nerve irritation, certain skin conditions can trigger a burning feeling localized to the skin. Contact dermatitis, an allergic reaction to a substance like a specific soap or metal, causes localized skin inflammation and a sensation of burning or stinging upon contact. Bacterial infections of the skin, such as cellulitis, cause the affected area to become intensely warm, swollen, and painful.
When to Seek Medical Evaluation
A persistent or unexplained burning sensation warrants medical attention. Consult a healthcare provider if the burning is ongoing, progressive, or interferes with daily activities or sleep. An evaluation is necessary to determine if a treatable underlying condition, such as a vitamin deficiency or diabetes, is the source of the nerve irritation.
Symptoms signaling a potentially serious or acute problem require immediate evaluation. Seek prompt medical care if the burning sensation has a sudden onset, rapidly spreads, or is accompanied by severe muscle weakness. Other urgent warning signs include paralysis, loss of bladder or bowel control, or the inability to feel pain or temperature in the affected area, as these can indicate a serious neurological emergency.