Nerve damage that causes pain, tingling, numbness, or weakness in the extremities is known as peripheral neuropathy, and it can cause impairment in sensation or both sensation and strength. It may affect a person’s ability to walk or participate fully in their everyday activities, which may negatively impact their quality of life.
When a person has peripheral neuropathy, one or more peripheral nerves are unable to communicate properly with the brain, skin, and muscles. This leads to gaps in sensation, strength, or discoordination in different body parts, such as the feet, legs, hands, or arms. This may make a person more prone to injury, if they can’t sense that they may be experiencing pain, particularly in their feet. Toe or foot amputations are sometimes required when injuries become advanced before they are discovered.
Peripheral neuropathy is very common among people with diabetes. Around 50% of people who have diabetes develop this condition over time. The longer a person has diabetes, particularly if it isn’t well-controlled, the more likely it is that he or she will develop peripheral neuropathy.
People are also more likely to develop peripheral neuropathy as they age. It most commonly occurs in people in their 70s and 80s.
There is no cure for peripheral neuropathy, but controlling underlying conditions (like diabetes) and managing symptoms may prevent the problem from worsening. This may help people avoid complications, including amputation.
“Certain medications can help minimize discomfort from peripheral neuropathy,” says Yale Medicine neurologist Benison Keung, MD. “However, addressing and treating the underlying cause is equally important in preventing symptoms from worsening.”
What is peripheral neuropathy
Peripheral neuropathy is a condition that develops when nerves in the peripheral nervous system, which is located outside of the brain and spinal cord, become damaged and don’t function properly. Often, peripheral neuropathy affects nerves in the extremities—feet, legs, hands, and/or arms. Nerve damage is often caused by diabetes-related complications, but it can occur from any number of conditions.
In healthy people, peripheral nerves communicate with the central nervous system (the brain and spinal cord). When peripheral nerves are damaged, they have difficulty sending or receiving messages to or from the brain. This may affect a person’s ability to feel sensations or control movement. Other symptoms people report include constant pain or burning sensations in the affected body parts.
Peripheral neuropathy typically affects the feet and lower legs, but it may also affect the hands and arms. Treatments are available to help control or minimize symptoms, although they may not be effective for everyone.
What causes peripheral neuropathy?
Diabetes is the most common cause of peripheral neuropathy. Having high blood sugar levels may damage small blood vessels and nerves in the body parts that are farthest from the heart, which include the feet, legs, hands, and arms.
Sometimes, peripheral neuropathy may occur if nerves are compressed. This may happen when someone experiences:
- Trauma that damages nerves
- Prolonged pressure on a nerve or nerves, due to posture or positioning
- Carpal tunnel syndrome, which affects the median nerve in the wrist
- Poorly fitting casts, braces, or crutches that compress a nerve or nerves
Other conditions may also cause peripheral neuropathy, including:
- Metabolic disease
- Rheumatoid arthritis
- Other autoimmune diseases
- Poor blood circulation in the legs
- Hepatitis C
- Vitamin B12 deficiency or another vitamin deficiency
- Alcohol use disorder
- Lead poisoning
- Mercury poisoning
- An underactive thyroid (hypothyroidism)
- Kidney disease
- Inherited nerve diseases
Certain chemotherapy drugs may also cause peripheral neuropathy as an unintended side effect.
What are the symptoms of peripheral neuropathy?
People who have peripheral neuropathy often experience one or more of these symptoms in their feet, legs, hands, and/or arms:
- Inability to feel temperature changes
People can experience symptoms on one or both sides of their body.
Peripheral neuropathy symptoms may change the way that people function in their everyday lives, leading to:
- Foot injuries, when people don’t realize that they have stepped on something sharp
- Gait changes
- Loss of muscle tone in their feet or hands
- Loss of balance
- Muscle twitches
- Swelling in the feet
- Charcot’s foot, a condition that damages the bones in the foot
What are the risk factors for peripheral neuropathy?
People who are at increased risk of peripheral neuropathy may have:
- A history of poorly controlled diabetes
- High blood sugar
- High blood pressure
- High triglyceride levels
- Nutritional deficiencies or toxicities
- Heavy alcohol consumption
- Rheumatoid arthritis, lupus, or other autoimmune diseases
- A family history of Charcot-Marie-Tooth Disease, familial amyloid polyneuropathy, or other inherited nerve conditions
A person’s risk increases with age; older adults are more likely to develop peripheral neuropathy than younger adults.
How is peripheral neuropathy diagnosed?
Doctors can diagnose peripheral neuropathy after obtaining a medical history, performing a physical exam, and ordering specific tests.
Before a physical exam, doctors will ask if you have been diagnosed with diabetes, an autoimmune disease, a vitamin deficiency, or another condition that increases the risk of peripheral neuropathy. They may ask about your alcohol intake, family history of inherited nerve conditions and personal history of trauma to the extremities.
During a physical examination, doctors pay close attention to the skin on your feet. Because the feet are affected by peripheral neuropathy most often, and because older people may not be able to examine their own feet very well, doctors may discover cuts, blisters, or other injuries that people haven’t noticed, especially if they have limited sensation in their feet.
A neurological exam is also important. Your reflexes will be checked and you’ll be asked to do simple tests to see if you can feel sensation, pressure, vibrations, heat, and cold in your feet. Your sense of balance and walking posture will also be evaluated.
Doctors may run the following diagnostic tests to rule out other conditions or confirm the presence of peripheral neuropathy:
- Blood tests, to check for low levels of vitamin B12 or other nutritional deficiencies that may be linked to peripheral neuropathy. Blood tests may also confirm that a patient has a different health condition.
- Nerve conduction tests and electromyography, which measure the way the electrical current flows through nerves and muscles and how well a patient’s nerves are functioning.
- Spinal tap or lumbar puncture, during which doctors remove a small amount of spinal fluid for analysis.
- Nerve biopsy, during which doctors remove a small piece of a patient’s nerve for analysis, after the patient receives local anesthesia.
- Imaging tests, such as MRI or CT scan, which may rule out other conditions.
How is peripheral neuropathy treated?
Lifestyle changes. When a patient is diagnosed with peripheral neuropathy because of diabetes or another underlying health condition, the best treatment may be to strive for better control of that condition, which may help to improve symptoms. For example, lifestyle changes (diet and exercise modifications) may be recommended and/or medication may be prescribed. People with diabetes are instructed about the importance of foot care—physically and visually examining their feet daily for any changes that may lead to foot injuries.
Medication. Medication may help relieve some symptoms of peripheral neuropathy. Doctors may recommend over-the-counter painkillers, or they may prescribe oral medications (including gabapentin, for neurological pain) or topical painkillers (such as adhesive patches) for patients who experience pain or burning. Some people may benefit from antidepressants or anti-seizure medication.
Physical Therapy. Some doctors recommend physical therapy, which may help patients regain the ability to move more freely and with better balance. Canes, walkers, or other assistive devices may also be recommended.
Surgery. In certain circumstances, doctors may recommend surgery, to alleviate pressure on a compressed nerve that continues to cause pain.
What is the outlook for people with peripheral neuropathy?
People with poorly managed peripheral neuropathy are more likely to experience foot ulcers—painful sores on the feet that don’t heal well—which may lead to infection and amputation. They may also experience a poorer quality of life if they are unable to manage symptoms like pain and burning, or if the condition affects their sense of balance or limits mobility.
However, it may be possible for some people with peripheral neuropathy to manage their foot health for better outcomes.
What makes Yale unique in its approach to peripheral neuropathy?
“The Yale Neuromuscular team has experienced physicians who understand the impact peripheral neuropathy may have in the lives of our patients,” says Dr. Keung. “Depending on the patient’s history and exam, we can tailor the management in terms of diagnostic testing, treatment, and rehabilitation to help provide the most comprehensive care possible.”