The sensation of a back that feels “on fire” is a distinct type of discomfort signaling an issue within the nervous system. This burning, shooting, or electric pain is commonly referred to as neuropathic pain, which arises from damage, disease, or dysfunction of the sensory nerves. Unlike the typical aching pain from a muscle strain (nociceptive pain), the burning feeling indicates that the nerves themselves are irritated or sending false signals to the brain. Pinpointing the source of this nerve irritation is the first step toward understanding the cause, which can originate deep within the spine, on the skin’s surface, or within the central nervous system.
Burning Sensation Caused by Nerve Compression
The most common structural cause for a burning sensation in the back is mechanical compression of the nerve roots as they exit the spinal column. When a nerve is physically squeezed or inflamed, it sends erratic signals to the brain, often interpreted as a burning or stinging pain. This nerve-related pain, known as radiculopathy, frequently radiates away from the spinal column, traveling down the path of the affected nerve.
A common manifestation of this mechanical irritation is sciatica, where compression affects the large sciatic nerve roots in the lower (lumbar) spine. This condition is frequently triggered by a herniated or bulging disc. The soft, jelly-like center of the spinal disc pushes through a tear in its outer wall, and the displaced material can chemically irritate or physically press against the adjacent nerve root. This causes sharp, burning pain that travels down the leg, sometimes accompanied by tingling or numbness.
Another structural issue is spinal stenosis, which involves the narrowing of the spinal canal or the small openings where nerve roots exit. This narrowing occurs due to age-related changes, such as the thickening of ligaments, the growth of bone spurs, or the degeneration of the spinal facet joints. As the space becomes restricted, the nerves are compressed, leading to a chronic burning sensation that often worsens during activities like walking or standing upright. The continuous pressure on the nerve sheath results in the characteristic burning pain and sometimes motor weakness in the lower limbs.
The mechanism of this burning is related to the nerve’s attempt to transmit sensory information while under duress. When compressed, the nerve fibers misfire, sending signals that the brain incorrectly translates as a high-intensity thermal sensation. This faulty signaling pathway is a direct consequence of the physical pressure disrupting normal electrical communication along the nerve. While most cases of nerve compression respond well to conservative treatments, persistent compression may lead to lasting damage if the pressure is not relieved.
Skin Conditions and Localized Irritation
While most burning back pain originates deep within the spinal structures, some causes are highly localized, affecting the nerves just beneath the skin’s surface. These conditions typically cause superficial pain, often accompanied by visible changes to the skin itself. The most significant cause in this category is Shingles (herpes zoster), a viral infection that directly attacks the peripheral nerves.
Shingles is caused by the reactivation of the varicella-zoster virus, which lies dormant in nerve tissue near the spine. When the virus reactivates, it travels along the nerve fibers to the skin, causing severe inflammation of the nerve cells. This intense nerve inflammation results in a deep, burning, or stinging sensation that often precedes the appearance of a characteristic rash by several days.
The pain associated with shingles is highly localized, appearing in a band-like pattern that follows the path of a single spinal nerve, known as a dermatome. It usually affects only one side of the body, a distinct feature that helps differentiate it from musculoskeletal back pain. Even after the rash has healed, some individuals experience a chronic burning pain known as postherpetic neuralgia, demonstrating the lasting effects of the viral attack on the nerve structure.
Other causes of localized burning can be superficial skin irritations that sensitize the nerve endings. A severe sunburn causes a thermal burn that inflames the skin and its underlying nerves, creating an intense, temporary burning sensation. Similarly, contact dermatitis or a localized allergic reaction can produce intense inflammation and irritation perceived as a surface-level burning or stinging.
Systemic and Chronic Pain Disorders
Beyond mechanical compression and localized skin issues, the burning sensation can be a manifestation of broader, systemic conditions that affect how the body processes pain signals. These disorders often involve chronic inflammation or a general sensitization of the nervous system, leading to widespread discomfort.
One such condition is Myofascial Pain Syndrome (MPS), which involves chronic, localized pain originating from taut bands within the muscles and the surrounding connective tissue (fascia). These localized, hyperirritable spots are called trigger points and can be felt as tender knots under the skin. While pressure on a trigger point causes local pain, it can also produce referred pain, where the discomfort is felt in an area distant from the actual source. This referred pain pattern can be interpreted as a deep, persistent burning sensation in the back or other areas, even though the structural problem lies within the muscle tissue.
Another complex cause is fibromyalgia, a chronic disorder characterized by widespread pain that can include a constant burning sensation in the back and multiple other areas. The underlying mechanism for this pain is central sensitization, a state where the central nervous system becomes overly responsive to stimuli. The brain and spinal cord amplify normal sensory input, causing both painful stimuli (hyperalgesia) and non-painful stimuli (allodynia) to be perceived as intense pain.
In central sensitization, the volume of pain signaling is turned up, resulting in chronic, often diffuse, burning discomfort that is inconsistent with any specific physical injury or compression. This condition is characterized by heightened sensitivity across multiple spinal segments. Understanding that the pain is related to nervous system processing, rather than a single compressed nerve, is necessary for managing these chronic systemic disorders.
Warning Signs and When to See a Doctor
While many causes of burning back pain are treatable with conservative care, certain accompanying symptoms signal a medical emergency requiring immediate attention. These “red flag” signs indicate progressing neurological compromise that could result in permanent damage.
The most concerning symptoms are associated with Cauda Equina Syndrome (CES), a rare condition where the bundle of nerves at the base of the spinal cord is severely compressed. Any recent onset of loss of bladder or bowel control, such as urinary retention or incontinence, must prompt immediate medical evaluation. This dysfunction shows that the nerves controlling these functions are under severe pressure.
Another urgent symptom is saddle anesthesia, which is numbness or altered sensation in the area that would touch a saddle, including the groin, buttocks, and inner thighs. The combination of this numbness with severe or worsening low back pain and any sudden, progressive weakness or loss of motor function in the legs are signs of a neurological emergency. Immediate care is also necessary if the burning pain is accompanied by fever, chills, or unexplained weight loss, as these may indicate an underlying infection or tumor affecting the spine.