doctor examining patient's hands with red denoting pain

What Causes Nerve Pain?

Whenever a nerve is irritated, either by compression, an injury or by changes in the blood, there may be symptoms of numbness, tingling or burning. We have all felt this—it is what we describe as the feeling of our arm or leg “falling asleep.”

Normally, these symptoms last for minutes after we lean our arm over the back of a chair. For some people, however, symptoms like this occur every day. Imagine this scenario: You feel constant tingling or a burning sensation in the feet. Maybe the feet feel cold or hot, or sensitive to touch. Maybe they feel like electrical zaps repeatedly, or the sensation reminds you of walking around with a sock or sand covering the skin of both feet. These are symptoms of peripheral neuropathy. In this condition, the integrity of the nerves is affected by a disease. 

The longest nerves of the body supply the toes and feet, and there is a tendency for neuropathy symptoms to affect the feet before any other place. Peripheral neuropathy tends to follow what is called a “stocking and glove” distribution, meaning that it affects the feet, lower legs and the hands.

There are many conditions that result in peripheral neuropathy. Common causes include excessive alcohol, a low vitamin B12 level or elevated blood glucose. Less common causes include adverse effects to chemotherapy, infections and inherited conditions. In some cases, the cause of peripheral neuropathy is not found; this is called idiopathic peripheral neuropathy.

Peripheral neuropathy is normally diagnosed after talking with a patient about symptoms, performing a physical exam and sometimes doing a special test called a nerve conduction study or EMG. In this test, small electric currents are applied to the skin. Different locations are monitored for how effectively nerves send this information up and down the arms or legs. In peripheral neuropathy, electrical conduction is impaired.

Treatment of peripheral neuropathy depends on finding the cause and addressing it. For example, people with a low vitamin B12 level can sometimes be cured by vitamin B12 replacement. In some cases, the goal of treatment is to minimize the symptoms. Physical therapy is useful to improve balance. Special medicines can be used to reduce pain symptoms related to neuropathy.

A couple of conditions that feel like peripheral neuropathy are worth mentioning. Diseases of the spine can sometimes cause symptoms like neuropathy. One difference is that spinal diseases tend to affect one side of the body more than the other, while neuropathy symptoms tend to be symmetric. Nerves can also be compressed on the inside—like a space inside the wrist.  Carpal tunnel syndrome is a condition that affects the median nerve, which supplies the hand. This may feel like peripheral neuropathy, but only one nerve is affected, and normally reducing the focus of compression is helpful. 

If you're concerned about pain you may be experiencing and are unsure of the cause, it's important to talk to your trusted healthcare provider. Schedule an appointment today.

Olav Jaren, MD, PhD is a neurologist at the Overlake Neuroscience Institute.