Neuropathy is caused by damage to the nerves that link the central nervous system (brain and spinal cord) to the rest of the body. These nerves are called the peripheral nerves.
- Muscle weakness
Peripheral nerves carry information:
- From the body to the nervous system. Nerves carry sensations of pain, temperature, soft touch, and joint position.
- From the central nervous system to the different muscles of the body. This allows you to move your face, vocal cords, and limbs.
- To and from organs and vessels. This controls functions such as heart rate and blood pressure.
Neuropathy pain can be:
- Generalized, which creates symptoms in a large area of the body. Sometimes the whole body is affected.
- Localized (focal), which affects a very specific body part or nerve.
Because nerves are located all over the body, the pain from neuropathy can occur anywhere. Depending on the cause of the neuropathy and the nerves affected, symptoms can be different for each person.
These symptoms can include:
- Loss of sensation. This may begin in your toes and gradually move up your foot and ankle. It may go on to affect your fingers and hands. This is typical of a metabolic or toxic neuropathy.
- Numbness, weakness, or tingling in any limb. For example, carpal tunnel syndrome is a focal neuropathy of a specific nerve in the wrist.
- Muscle weakness and wasting. Some neuropathies damage the “motor” nerves that control the muscles. This leads to weakness and muscle wasting. Some diseases only affect the motor nerves, such as multifocal motor neuropathy and ALS (Lou Gehrig’s disease).
Neuropathy pain can cause:
- Burning or tingling feelings.
- Intense, electric shock-like sensations. Intense pain is characteristic of the nerve damage caused by diseases such as shingles.
Screening and Diagnosis
Knowing the underlying cause of your neuropathy will help us treat it effectively. Sometimes the cause is obvious, such as a recent injury.
To diagnosis your condition, we will:
- Ask you about your symptoms and medical history.
- Examine you. We’ll look for signs of other medical problems that can mimic the symptoms of neuropathy. For example, a heart attack can cause sensory symptoms in the left arm. Stroke and multiple sclerosis patients can also suffer from numbness and weakness.
- Order lab tests. These help us rule out other disorders such as diabetes or a thyroid condition.
Neuropathy has many potential causes. We may also order tests for conditions based on your medical or family history.
There can be many potential causes of neuropathy. They include these basic categories.
Traumatic. Causes of neuropathy from trauma include:
- Blunt trauma. A long bicycle ride can compress a nerve in the wrist, for example.
- Deep wound, such as a knife wound.
- Stretch injuries. A motorcycle accident, for example, can stretch or tear nerves in the neck and shoulder.
- Repetitive use. Repetitive use injuries can damage the nerves. Carpal tunnel syndrome is a common example.
Metabolic. Your metabolism is the chemical process in your body that breaks down food into energy. When these don’t work properly, nerve damage can occur.
This is frequently seen in patients with diabetes. Other metabolic conditions that can damage nerves include:
- Chronic renal failure
- Vitamin deficiencies
Toxic. Many substances are toxic (harmful) to the nerves. They include medications and alcohol. Exposure to toxins such as lead and other heavy metals damage nerves as well.
Inflammatory. Inflammatory or autoimmune disorders can affect the nerves. The most dramatic of these is Guillain-Barre syndrome. Nerve inflammation from this syndrome gets worse very quickly. This can lead to complete paralysis in a few days.
Hereditary. There are many inherited (born with it) diseases that can damage nerves. These are seen more often in younger patients.
Infectious. Some infections can cause nerve damage, such as HIV, Lyme disease, syphilis, and West Nile virus.
Idiopathic (unknown cause). Some disorders that cause neuropathy may have no diagnostic tests to identify them or are not yet well understood. Neuropathy also seems to be part of the aging progress. Up to 10 percent of the population over age 60 may have progressive numbness of the feet and toes.
To help prevent neuropathy, you can:
- Keep blood sugar under control. Diabetes is one of the most common causes of neuropathy. High blood sugar can cause nerve damage, especially in your hands and feet. We’ll work with you to manage your blood sugar. It’s also important to exercise regularly and monitor your feet for any signs of nerve damage.
- Use alcohol in moderation. Alcohol abuse can cause neuropathy. If you do drink, use alcohol in moderation. Talk to us if you think you have a problem with alcohol.
- Avoid repetitive movements. Pay attention to ergonomics at work. Try to avoid ongoing repetitive movements.
Neuropathic pain can interfere with your sleep and normal daily activities. Mild pain can be treated with over-the-counter medications such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin).
Many of the drugs used to treat neuropathy pain have side effects. They can also cause health problems if you combine them with other medications. We will discuss which medications are best for you.
These medications decrease nerve membrane irritability and interrupt pain processing. They should be taken daily. Side effects include:
- Very rarely, complications that we’ll need to monitor
Antidepressants control the perception of pain. However, they can also cause:
- Dry mouth
Antidepressants should be taken daily. Patients with some types of glaucoma and certain cardiac conditions should avoid these medications.
We only recommend narcotics for patients with chronic neuropathic pain that doesn’t respond to other forms of pain relief. Although these drugs provide immediate pain relief, they’re habit-forming, and their effect decreases over time. They can cause:
- Other complications
Topical agents, such as lidocaine, are applied to the skin as an ointment or skin patch. They’re sometimes effective for localized pain caused by shingles or burning feet. Because they’re not taken orally, they don’t cause side effects throughout the body.
Guidelines for taking medications
We’ll advise you on how to take anticonvulsants and antidepressants. These need to be taken daily since it may take some time for them to build up in your body. Don’t expect them to work immediately. They should never be used on an as-needed basis.
We’ll also advise you to slowly increase the dose over time to reduce the side effects and increase the benefits. If one type of medication doesn't work, we’ll often suggest you try another medication. We may also try a combination of drugs.
Transepidermal nerve stimulation (TENS)
A TENS machine provides low-current electrical stimulation through the skin that can control or reduce localized neuropathic pain.
Some people find that pain gets better for a while after acupuncture. We can refer you to a trained acupuncturist.
Dorsal column stimulators (DCS)
A DCS is a nerve stimulator that’s implanted surgically into the spinal cord. These devices can be helpful in severe cases where nothing else has worked to control pain.
An intrathecal pump is a surgically implanted device. It infuses pain medication directly into the cerebral spinal fluid surrounding the spinal cord. Like DCS, this is an invasive treatment that’s only considered when all medications have been tried and none are effective.
Many people have symptoms that progress very slowly and aren’t disabling. However, with most types of generalized neuropathy, symptoms gradually get worse over time. This often occurs when diabetes is the cause.
If motor function is affected, most people can continue to walk. Sometimes braces, canes, or walkers are needed when neuropathy is ongoing. If your symptoms get worse, let us know immediately so we can work together to manage them.
Kaiser Permanente has several support groups for patients with neuropathy and diabetes. Ask us about them or contact our local Health Education Department.
Weakness can cause difficulty with walking, gripping objects, or getting out of bed. This can result in falls. Our occupational therapists can help you adapt to these limitations.
If you have muscle weakness in your foot and ankle, this can prevent you from lifting your foot. A physical therapist can fit ankle braces to prevent this and help you walk.
Loss of sensation can lead to more injuries, particularly in the feet. To prevent injury:
- Inspect your feet regularly. Look for cuts or abrasions you can’t feel because of numbness. These may become infected unless they’re treated.
- Wear shoes always. Keep your house free of clutter to reduce the risk of tripping or stepping on objects.
- Add lighting. Numbness in the feet and/or legs can affect your balance, particularly when walking at night or when your eyes are closed in the shower. Place night lights in and around your house, as well as guard rails in the shower and bathroom.
If you have an emergency medical condition, call 911 or go to the nearest hospital.
An emergency medical condition is any of the following:
(1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.
This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.