Peripheral neuropathy
DEFINITION
Peripheral neuropathy, a result of damage to your peripheral nerves, often causes weakness, numbness and pain, usually in your hands and feet. It can also affect other areas of your body.
Your peripheral nervous system sends information from your brain and spinal cord (central nervous system) to the rest of your body. Peripheral neuropathy can result from traumatic injuries, infections, metabolic problems, inherited causes and exposure to toxins. One of the most common causes is diabetes mellitus.
People with peripheral neuropathy generally describe the pain as stabbing or burning. Often, there’s tingling. In many cases, symptoms improve, especially if caused by a treatable underlying condition. Medications can reduce the pain of peripheral neuropathy.
CAUSES
A number of factors can cause neuropathies, including:
- Alcoholism. Poor dietary choices made by alcoholics can lead to vitamin deficiencies.
- Autoimmune diseases. These include Sjogren’s syndrome, lupus, rheumatoid arthritis, Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy and necrotizing vasculitis.
- Diabetes. More than half of people with diabetes develop some type of neuropathy.
- Exposure to poisons. Toxic substances include heavy metals or chemicals.
- Medications. Certain medications, especially those used to treat cancer (chemotherapy), may cause peripheral neuropathy.
- Infections. These include certain viral or bacterial infections, including Lyme disease, shingles (varicella-zoster), Epstein-Barr virus, hepatitis C, leprosy, diphtheria and HIV.
- Inherited disorders. Disorders such as Charcot-Marie-Tooth disease are hereditary types of neuropathy.
- Trauma or pressure on the nerve. Traumas, such as motor vehicle accidents, falls or sports injuries, can sever or damage peripheral nerves. Nerve pressure can result from having a cast or using crutches or repeating a motion many times, such as typing.
- Tumors. Growths, cancerous (malignant) and noncancerous (benign), can develop on the nerves themselves or they can put pressure on surrounding nerves.
- Vitamin deficiencies. B vitamins, including B-1, B-6 and B-12, vitamin E and niacin are crucial to nerve health.
- Bone marrow disorders. These include abnormal protein in the blood (monoclonal gammopathies), a form of bone cancer (osteosclerotic myeloma), lymphoma and amyloidosis.
- Other diseases. These include kidney disease, liver disease, connective tissue disorders and an underactive thyroid (hypothyroidism).
SYMPTOMS
Every nerve in your peripheral system has a specific function, so symptoms depend on the type of nerves affected. Nerves are classified into:
- Sensory nerves that receive sensation from the skin such as temperature, pain, vibration or touch
- Motor nerves that control how your muscles move
- Autonomic nerves that control functions such as blood pressure, heart rate, digestion and bladder
Signs and symptoms of peripheral neuropathy may include:
- Gradual onset of numbness and tingling in your feet or hands, which may spread upward into your legs and arms
- Sharp, jabbing or burning pain
- Extreme sensitivity to touch
- Lack of coordination and falling
- Muscle weakness or paralysis if motor nerves are affected
If autonomic nerves are affected, signs and symptoms may include:
- Heat intolerance and altered sweating
- Bowel, bladder or digestive problems
- Changes in blood pressure, causing dizziness or lightheadedness
Peripheral neuropathy may affect one nerve (mononeuropathy), two or more nerves in different areas (multiple mononeuropathy) or many nerves (polyneuropathy).
When to see a doctor
Seek medical care right away if you notice unusual tingling, weakness or pain in your hands or feet. Early diagnosis and treatment offer the best chance for controlling your symptoms and preventing further damage to your peripheral nerves.
