Neuropathy is a general term describing damage to the nerves or diseases, symptoms, or side effects that impact the nerves.
Neuropathy can affect both the cranial nerves—nerves that originate in the brain and travel to other areas of the head and upper body—and peripheral nerves. Peripheral nerves originate in the spinal cord and branch out to the rest of the body. When neuropathy affects the cranial nerves, the condition is called cranial neuropathy. When neuropathy affects the peripheral nerves, the condition is called peripheral neuropathy.
Damage to the peripheral nervous system can distort and interrupt the messages carried between the brain and spinal cord and the rest of the body. This often causes weakness, numbness, and pain, usually in the hands and feet.
Peripheral neuropathy can be classified into two broad categories:
- Mononeuropathy involves damage to a single nerve or nerve group.
- Polyneuropathy involves damage to multiple nerves.
There are three types of peripheral nerves. Some neuropathies affect all three types, while others only involve one or two.
- Motor nerves send signals from your brain and spinal cord to the muscles in your body that control voluntary movements, such as walking and talking.
- Autonomic nerves control automatic functions, such as breathing and the muscles involved in inhaling and exhaling, blood pressure, heart rate, and digestion.
- Sensory nerves receive sensation from the skin, such as temperature or pain, and send the information to the central nervous system.
How common is neuropathy?
Neuropathy is a common condition. An estimated 20 million people in the United States have some form of peripheral neuropathy.
Who gets neuropathy?
Neuropathy can affect anyone, as it has many types and causes. People with diabetes are especially at risk for developing neuropathy because high blood sugar levels over a long period of time can damage nerves.
Other causes of neuropathy include:
- Trauma, such as car crashes, sports injuries, and falls
- Tumors that grow on a nerve itself or compress surrounding nerves
- Autoimmune disorders, such as rheumatoid arthritis, lupus, Guillain-Barre syndrome, and chronic inflammatory demyelinating polyneuropathy
- Exposure to toxic substances
- Infections, such as Lyme disease, shingles, leprosy, HIV, and Hepatitis C
- Kidney disease
- Medications, especially chemotherapy drugs
- Metabolic and endocrine disorders, such as an underactive thyroid gland (hypothyroidism)
- Vitamin deficiencies
- Inherited disorders, such as Charcot-Marie-Tooth disease
- Broken or dislocated bones that compress surrounding nerves
- Carpal tunnel syndrome
How is neuropathy diagnosed?
To diagnose neuropathy and possibly identify the cause, your doctor may conduct the following tests:
- Physical exam
- Neurological exam
- Imaging tests, such as a CT scan or an MRI scan
- Nerve conduction studies
- Nerve biopsy
- Skin biopsy
- Blood tests
Symptoms can vary depending on whether motor, autonomic, or sensory nerves are damaged. Symptoms can be painful and potentially debilitating, but few forms of neuropathy are fatal.
Symptoms of Motor Nerve Damage
- Muscle weakness or paralysis
- Muscle cramps and twitching
- Muscle atrophy (decrease in muscle mass)
- Decreased reflexes
Symptoms of Sensory Nerve Damage
- Gradual onset of numbness and tingling in your feet or hands, which may spread upward into your legs and arms
- Decrease in pain sensation
- Inability to feel changes in temperature
- Extreme sensitivity to touch (allodynia)
- Loss of reflexes
- Loss of awareness of your position and orientation in relation to other people and objects, which can affect your ability to coordinate complex movements like walking or fastening a button
Symptoms of Autonomic Nerve Damage
- Inability to sweat normally
- Problems controlling body temperature
- Loss of bladder control
- Gastrointestinal problems
- Difficulty eating or swallowing
- Dizziness, lightheadedness, or fainting when standing suddenly due to changes in blood pressure
Symptoms of peripheral neuropathy can vary greatly. Contact a medical professional if you are experiencing any symptoms.
Treating the underlying cause of neuropathy can help relieve symptoms. Depending on the cause, treatment may include:
- Medication changes
- Replacing a vitamin deficiency
- Controlling your blood sugar
- Eliminating alcohol use
- Surgery to alleviate pressure on nerves
- Physical therapy to help with muscle weakness
- Transcutaneous electrical nerve stimulation
- Wearing hand or foot braces
Because neuropathy can have such a wide variety of underlying causes, determining the root of your nerve problem is key to determining the treatment that is needed. At Barrow Neurological Institute at Dignity Health St. Joseph’s Hospital and Medical Center, our neurologists have experience in determining the cause of nerve problems, and the patience to work with you until a correct diagnosis is obtained and a treatment can be identified.
- Date of last review: January 11, 2017
- Author: Erik Ortega, MD