What causes burning feet syndrome?
The symptoms of burning feet syndrome can result from many different conditions or diseases. These include:
- Nerve damage or entrapment. There are many possible causes of nerve damage. It may occur due to various illnesses, back injuries or slow breakdown (degenerative changes) of the spine, surgery, use of chemotherapy drugs or other medications, or exposure to toxins.
- Peripheral neuropathy. This is one of the most common causes of burning feet syndrome. It occurs when the peripheral sensory nerves connecting the spinal cord to the extremities are damaged. People who have had diabetes for a long time, or those with poorly controlled blood glucose levels, are more likely to develop peripheral neuropathy. Diabetic peripheral neuropathy develops gradually and may worsen over time. Other conditions that can cause peripheral neuropathy include chemotherapy agents, hereditary diseases, auto-immune disorders (including rheumatoid arthritis), exposure to toxic chemicals, infections, kidney failure, alcoholism, and nutritional imbalances (vitamin B deficiency, malabsorption syndrome).
- Tarsal Tunnel Syndrome. The tarsal tunnel is a narrow space inside the ankle near the ankle bones. Compression or squeezing of the posterior tibial nerve (the nerve behind the largest long bone of the lower leg) inside the tarsal tunnel can result in sensations of burning, tingling, or pain in parts of the feet. The inner ankles and calves of the legs can also be affected.
- Morton’s neuroma. Nerve tissue may thicken between the bones at the base of the toes, causing pain. Shoes that are too tight can cause this type of neuroma, although it may also result from sports injury, stress, or abnormal position or movement of the foot.
- Complex regional pain syndrome. This rare, yet extremely painful nerve disorder, may occur after an injury or surgery.
- Charcot-Marie-Tooth disorder. This inherited neurological disorder may cause damage to the peripheral nerves of the legs and feet. The damage becomes worse over time. Charcot-Marie-Tooth affects the muscles and nerves of the extremities resulting in abnormal weakness and lifting of the arches of the feet. Abnormal stresses on the feet can predispose to stress fractures and frequently these individuals will require bracing to function properly.
- Endocrine or metabolic disorders
- Diabetes mellitus. Type 1 and type 2 diabetes may affect the peripheral nerves of the body, especially the sensory nerves of the feet and legs. High glucose levels or poorly controlled diabetes can cause damage to the peripheral nerves, especially over the long term. High blood glucose levels affect the transmission of signals from these nerves and can weaken blood vessel walls.
- Hypothyroidism. An underactive thyroid gland may cause a sensation of burning in the feet, along with weight gain, dry skin or fatigue.
- Athlete’s Foot (tinea pedis). This fungal infection is caused by mold-like fungi called dermatophytes that grow in moist, warm areas of the skin. Damp shoes and socks and humid environments allow the fungi to grow and spread. Symptoms of athlete’s foot may include itching, burning, and stinging between the toes and the soles of the feet.
- Other causes
- Erythromelalgia/Erythermalgia. This rare disorder can result in intense burning pain, increased skin temperature, and visible redness (erythema) of the toes and soles of the feet. The hands may also be affected. Its exact cause is unknown. Attacks may occur only at certain times (flare-ups) and last from several minutes to several days, or the burning pain might be continuous. The affected area may become tender, swollen, and warm.
- Footwear that is too tight or does not fit properly. Tight shoes or stockings can irritate sensitive feet or put pressure on certain parts of the foot.
- Stress due to exercise or physical injury.
- Allergies. Materials used to make shoes or socks may trigger symptoms.
- Contact dermatitis. Dyes or chemical agents used to tan leather might result in skin irritation.
- Other causes include chronic mountain sickness, Gitelman syndrome, Leishmaniasis, multiple sclerosis, psychological disorder (psychosomatic), hereditary causes, and unknown causes (idiopathic)
What are the most common symptoms of burning feet syndrome?
The most common symptoms include:
- Sensations of heat or burning, often worsening at night
- Numbness in the feet or legs
- Sharp or stabbing pain
- Feeling of heaviness in the feet
- Dull ache in the feet
- Skin redness or excess warmth
- Prickling or tingling or a feeling of “pins and needles”
How is burning feet syndrome diagnosed?
Since there are no tests to objectively measure the intensity of foot pain or burning, your doctor will try to determine the underlying cause of the symptoms.
- Physical examination. Your doctor will ask you about your medical history, including any physical symptoms you have and medications that you are taking. He or she will test your reflexes and examine your feet for signs of infection, injury, or other problems.
- Blood tests. Tests may be ordered to measure your blood glucose level or screen for nutritional deficiencies or endocrine disorders. A complete blood count usually is performed. Other lab work may include serum and urine electrolytes (magnesium, sodium, potassium, vitamin B levels and chloride).
- Nerve function tests. Electrodiagnostic tests may be ordered in the case of suspected nerve damage.
- Electromyography. This test measures the electrical activity of a muscle and is performed to see how the muscle responds to nerve stimulation. A very thin needle is inserted through the skin into the muscle to measure the muscle’s activity as it contracts and relaxes. It is performed to determine the cause of pain, numbness or tingling.
- Nerve conduction velocity test. This test is done to assess the speed at which electrical impulses move along a nerve. It is performed to differentiate between true nerve disorders and conditions in which muscles are affected by a nerve injury. Flat electrodes are placed on the skin along the nerve pathway and a low-intensity current is applied.