For 52-year-old Rajesh, a shopkeeper in Hyderabad, the problem began as a mild tingling in his toes. "I thought it was because I was standing all day," he says. Within a few months, however, his feet began to burn at night. "Sometimes it felt as if I was walking on hot sand, even when I was lying in bed."
Rajesh's experience is familiar to many. Tingling, pins and needles, numbness and burning sensations in the feet are often dismissed as tiredness, ageing, poor circulation or simply standing for too long. However, persistent symptoms can sometimes be the first clue to an underlying medical condition.
One of the commonest explanations is peripheral neuropathy, damage to the nerves outside the brain and spinal cord. The good news is that identifying the cause early can often prevent further nerve damage and, in some cases, significantly improve symptoms.
Why do the feet tingle or burn?
The nerves supplying our feet carry information about touch, temperature, pain and position to the brain. When these nerves become damaged or irritated, abnormal signals may be generated. The result can be tingling, pins and needles, burning, electric-shock-like sensations, numbness or pain.
Symptoms often begin in the toes and gradually spread upwards in a characteristic 'stocking' pattern. They may affect both feet and are frequently worse at night. In some people, even the touch of a bed sheet can become uncomfortable.
For many patients, the symptoms are more than a minor annoyance. Poor sleep, difficulty walking, reduced physical activity and anxiety about the cause can all affect quality of life.
Diabetes: one of the commonest causes
In Rajesh's case, a medical evaluation revealed something unexpected: he had diabetes.
Diabetes is among the leading causes of peripheral neuropathy. Persistently elevated blood glucose can damage nerves and the small blood vessels that nourish them.
Burning and tingling may be among the earliest symptoms of diabetic nerve damage. Initially, the small nerve fibres that carry pain and temperature sensations are often affected, causing burning feet even when routine examination appears relatively normal. Later, numbness and reduced sensation may develop.
Importantly, nerve damage is not restricted to people with established diabetes. Peripheral neuropathy can also occur in people with prediabetes, particularly when metabolic health is poor or other risk factors such as obesity and abnormal blood fats are present.
This is especially relevant in India, where diabetes and prediabetes are common and many people remain unaware of their elevated blood glucose levels. Therefore, a person with unexplained burning or tingling in the feet should have their blood glucose evaluated, even if they have never been diagnosed with diabetes.
Good diabetes control, regular exercise, maintaining a healthy weight and avoiding tobacco can help reduce the risk of progression.
Vitamin B12 deficiency: An important and treatable cause
Vitamin B12 deficiency deserves special attention because it is both relatively common and treatable.
B12 is essential for healthy nerves and blood cells. Deficiency can cause tingling, pins and needles, numbness, burning sensations, imbalance and difficulty walking. In severe or prolonged deficiency, nerve damage may become difficult to reverse completely.
A common misconception is that B12 deficiency can occur only when a person is anaemic. This is not true. Neurological symptoms may occur even without anaemia or an abnormal blood count.
People at increased risk include those with a diet low in animal-source foods, older adults and those with problems absorbing B12. Long-term use of medicines such as metformin, commonly prescribed for diabetes, and acid-suppressing medicines may also contribute in some individuals.
Treatment with oral or injectable B12 can be highly effective, particularly when started early. However, the underlying cause must also be identified, as some people require long-term replacement.
Other common causes
Burning and tingling feet have many possible causes. These include:
Thyroid disease: An underactive thyroid can occasionally cause peripheral neuropathy
Kidney disease: Severe kidney dysfunction can lead to nerve damage
Alcohol use: Excessive long-term alcohol consumption can damage nerves directly and through nutritional deficiencies
Vitamin abnormalities: While B12 deficiency is particularly important, other nutritional problems can affect nerves. Interestingly, excessive vitamin B6 intake from unnecessary supplements can also cause neuropathy
Certain medicines: Some chemotherapy drugs and other medications can damage peripheral nerves
Nerve compression: Conditions such as tarsal tunnel syndrome can cause tingling or burning, usually in a more localised area
Infections and autoimmune diseases: Certain infections and immune-mediated disorders can cause neuropathy
Sometimes, despite detailed investigations, no definite cause is found. This is called idiopathic peripheral neuropathy.
Could it indicate a serious disease?
Most cases of gradually developing burning feet are not medical emergencies. Nevertheless, persistent symptoms should not simply be ignored.
A doctor should evaluate symptoms that are persistent, worsening or spreading upwards. Urgent assessment is particularly important if tingling is accompanied by rapidly developing weakness, difficulty walking, loss of bladder or bowel control, severe imbalance or sudden onset of symptoms.
In some situations, the problem may originate not in the peripheral nerves but in the spinal cord or brain. Persistent sensory symptoms accompanied by weakness or significant difficulty walking deserve medical evaluation.
How is the cause diagnosed?
The most important first step is a careful medical history and neurological examination.
Depending on the symptoms, commonly recommended tests may include blood glucose and HbA1c, vitamin B12, thyroid function and kidney function. Other tests may be needed depending on the clinical situation.
Nerve conduction studies and electromyography can assess large nerve fibres. However, people with early small-fibre neuropathy may have normal nerve conduction studies despite significant burning pain.
What are the treatment options?
Treatment has two important components.
First, treat the underlying cause. This may involve improving diabetes control, correcting B12 deficiency, treating thyroid or kidney disease, stopping an offending medicine or reducing alcohol consumption.
Second, control the symptoms. Neuropathic pain often does not respond well to ordinary painkillers alone. Depending on the individual, doctors may prescribe medicines such as duloxetine, amitriptyline, pregabalin or gabapentin.
What is the long-term outlook?
The outcome depends largely on the cause and how early it is identified.
When the underlying problem is reversible, such as vitamin B12 deficiency or a medication-related problem, symptoms may improve considerably with appropriate treatment. However, nerve recovery can be slow and may take months.
In conditions such as long-standing diabetes, the aim is often to prevent further nerve damage while controlling pain and protecting the feet. Even when complete recovery is not possible, many people can achieve substantial improvement in symptoms and quality of life.
For Rajesh, better diabetes management, regular walking and treatment for his nerve pain gradually improved his sleep and daily comfort. "I only wish I had got it checked earlier," he says.
The key message is simple: persistent tingling or burning in the feet should not be dismissed as "just tiredness" or a normal part of ageing. It may be the body's early warning signal of nerve damage, and sometimes, identifying the cause early can make all the difference.
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
