A burning sensation in the forearms, often described as a sharp sting, warmth, or prickling feeling, is an abnormal nerve sensation known as paresthesia or dysesthesia. This symptom indicates that the nervous system is reporting irritation or damage somewhere along its pathway. The burning may originate locally in the muscles or tendons, or it could signal a major nerve compression or a systemic condition affecting nerve health throughout the body. Understanding the location and timing of this sensation helps determine the underlying cause.
Overuse and Muscular Strain
The most common causes of forearm burning are related to physical exertion and localized tissue stress from activity. When forearms are subjected to intense, unaccustomed exercise, the muscles can experience a temporary burning sensation during the workout. This feeling is caused by the accumulation of hydrogen ions in the muscle tissue, a process called acidosis. This temporary drop in the muscle’s pH triggers sensory nerves, signaling the muscle to slow down and protect itself from further fatigue.
A more persistent, localized burning is often a hallmark of tendinopathy, which is irritation or injury to the tendons connecting muscle to bone. This condition is commonly seen in the elbow region, where the forearm tendons originate. For example, Lateral Epicondylitis, or “Tennis Elbow,” causes a burning pain on the outer side of the forearm near the elbow due to repetitive strain of the wrist extensor tendons. Conversely, Medial Epicondylitis, or “Golfer’s Elbow,” presents with a burning sensation on the inner side of the forearm, reflecting an issue with the wrist flexor tendons.
The burning sensation in tendinopathy results from the body’s immune response to microscopic tears or degeneration within the tendon fibers. This inflammation releases chemical mediators that sensitize local pain receptors, causing the feeling of warmth and burning. Repetitive Strain Injuries (RSIs) often begin as muscle fatigue and strain before progressing to tendon involvement. RSIs develop when tissues are overloaded by repetitive movements, such as typing, leading to chronic inflammation and persistent discomfort.
Nerve Entrapment Syndromes
When the burning sensation is accompanied by tingling, numbness, or weakness, the cause is often a mechanical compression of one of the major peripheral nerves that travel through the forearm. This compression occurs when a nerve is physically squeezed by surrounding tissues, such as bone, cartilage, or ligaments. The squeezing disrupts the nerve’s electrical signaling, and the resulting abnormal signal transmission is what the brain interprets as a burning or “pins and needles” sensation.
One of the most recognized of these conditions is Carpal Tunnel Syndrome (CTS), which involves the median nerve being compressed as it passes through a narrow channel in the wrist. While CTS primarily affects the thumb, index, and middle fingers, the burning discomfort can radiate upward into the forearm. Since the median nerve is responsible for both sensation and motor function, compression can also lead to weakness in the hand.
Another common site for nerve compression is the elbow, leading to Cubital Tunnel Syndrome. This occurs when the ulnar nerve is squeezed as it passes through a tunnel on the inner side of the elbow. Symptoms typically involve burning and tingling in the ring and little fingers, but the pain frequently projects up the inner forearm. Less commonly, compression of nerve roots higher up in the neck and shoulder causes Thoracic Outlet Syndrome (TOS). TOS affects the entire arm and hand because nerves and blood vessels are compressed between the collarbone and the first rib, often mimicking lower-level entrapments.
Underlying Systemic and Metabolic Conditions
In cases where the burning sensation is present in both forearms and perhaps other extremities, it can be a manifestation of a systemic health issue. This widespread nerve damage is known as peripheral neuropathy, where the small nerve fibers responsible for transmitting sensation are impaired. The most common systemic cause of peripheral neuropathy is Diabetes Mellitus, where prolonged high blood sugar levels damage the tiny blood vessels supplying the nerves. This damage causes the nerves to malfunction and send pain signals.
Nutritional deficiencies can also contribute to nerve dysfunction, particularly a lack of B vitamins. Insufficient Vitamin B12 or Vitamin B6 is necessary for maintaining healthy nerve sheaths and function, and a deficiency can lead to neuropathy symptoms, including burning. Similarly, an underactive thyroid gland, known as hypothyroidism, can cause fluid retention that puts pressure on peripheral nerves or directly impact nerve health through metabolic changes.
Other systemic factors can cause burning by affecting blood flow or triggering immune responses. Autoimmune diseases, such as Lupus or Rheumatoid Arthritis, cause inflammation that can damage nerve tissue or their supplying blood vessels. Vascular issues like Raynaud’s phenomenon cause small arteries to spasm in response to cold or stress. This restricts blood flow and leads to a painful, burning sensation as the extremity re-warms and circulation returns.
Guidance on Seeking Professional Care
It is prudent to seek professional medical advice if the forearm burning sensation persists beyond a few days of rest and self-care, or if it interferes with daily activities. Initial self-care often involves simply resting the affected limb and avoiding the activity that triggered the pain. Applying ice or heat can also help to manage localized inflammation and discomfort.
Immediate medical attention is warranted if the burning is accompanied by “Red Flag” symptoms. These urgent signs include a sudden onset of numbness, noticeable muscle weakness, or a complete loss of function in the hand or fingers. Emergency evaluation is also required for symptoms that worsen rapidly, occur suddenly on only one side of the body, or are accompanied by chest pain or difficulty breathing.
A primary care physician is the appropriate starting point for diagnosis, as they can order blood tests to check for systemic causes like diabetes or vitamin deficiencies. Depending on the suspected cause, they may refer you to a specialist. A neurologist can perform tests like nerve conduction studies to assess nerve function, while an orthopedist or physical therapist handles musculoskeletal issues. Prompt diagnosis ensures that progressive issues, such as severe nerve entrapment or underlying metabolic disorders, are addressed before permanent damage occurs.