Diabetic Neuropathy

Overview, Causes, & Risk Factors

Diabetic neuropathy is an injury to the nervous system caused by underlying diabetes mellitus.

What is going on in the body?

Diabetes mellitus, often called diabetes, is a condition that affects the body's ability to regulate the level of glucose in the blood. Glucose is the main form of sugar in the body. It is suspected that high blood glucose levels are neurotoxic. This is another way of saying that they have a poisonous effect on the nerves. If blood glucose levels are elevated significantly for a period of time, the nerves can be permanently damaged.

What are the causes and risks of the disease?

Diabetic neuropathy is a complication of high blood glucose in people who have diabetes.

Symptoms & Signs

What are the signs and symptoms of the disease?

Some evidence of neuropathy is present in 60% of all individuals with diabetes. Thirty percent to 40% of those individuals have not yet developed symptoms. When symptoms do occur, they may include any or all of the following:

abdominal distress

back pain

chest pain

constipation or diarrhea

diminished sexual response and erectile dysfunction

dizziness

extreme sensitivity to touch

gastroparesis, a condition in which the stomach empties too slowly

hearing impairment

heart attack

loss of balance and coordination

nausea and vomiting

numbness or burning in the hands, feet, and legs

orthostatic hypotension, or a drop in blood pressure when standing up

problems with urination that lead to urinary tract infections

visual impairment, including double vision

weakness

Diagnosis & Tests

How is the disease diagnosed?

The diagnosis of diabetic neuropathy begins with a medical history and physical exam. The healthcare provider may order tests such as the following:

blood glucose tests

electromyography, or EMG, studies, which record electrical impulses in muscles

nerve biopsies to look for nerve damage

nerve conduction velocity, or NCV, studies, which measure the speed of nerve impulses

screening tests to measure sensation in the feet

ultrasounds to look for damage to internal organs

Prevention & Expectations

What can be done to prevent the disease?

A 10-year study by the National Institute of Diabetes and Digestive and Kidney Diseases showed that blood glucose control is key in preventing diabetic neuropathy. People who kept their blood glucose levels as close to the normal range as possible were able to delay the onset and progression of neuropathy.

Diabetic neuropathy is also more common in people who are more than 40 years old. It is more likely in those who smoke. Heredity also plays a role, since some people are more susceptible to nerve damage than others.

What are the long-term effects of the disease?

If diabetic neuropathy is not treated effectively, it can have devastating effects. Muscles may waste and become weak. Sensory involvement may produce progressive numbness and pain. In extreme cases, sensory involvement can lead to diabetic ulcers and amputation.

What are the risks to others?

Diabetic neuropathy is not contagious, and poses no risk to others.

Treatment & Monitoring

What are the treatments for the disease?

Good control of blood glucose levels prevents further nerve damage. Low glucose levels can reverse the pain or numbness from nerve damage.

Treatment for pain caused by diabetic neuropathy includes the following therapies:

acupuncture

biofeedback

hypnosis

massage

physical and occupational therapies for treatment of motor involvement

regular moderate walking

relaxation training

transcutaneous electronic nerve stimulation, also called TENS, which uses small bursts of electricity to block pain signals

warm baths

wrapping the legs in elastic stockings

The following medications may be used for treatment of pain caused by diabetic neuropathy:

antidepressant medications, such as amitriptyline and fluphenazine, to relieve pain

capsaicin, a topical cream that helps relieve pain

codeine, a powerful narcotic, for short term relief of severe pain

medications commonly used for seizures, which may relieve nerve pain. These include carbamazepine and phenytoin sodium.

over-the-counter analgesic ointment

pain medications for burning, tingling, or numbness. These include aspirin, acetaminophen, and ibuprofen.

Gastroparesis may be treated by taking the following steps:

Avoid excess fat in the diet.

Eat less fiber.

Eat small, frequent meals.

Medications that can be used in the treatment of gastroparesis are as follows:

erythromycin, an antibiotic

medications that reduce excess stomach acid

metoclopramide, a medication that speeds digestion

Diarrhea and other intestinal problems may be treated with the following:

antibiotics, such as tetracycline

clonidine, a medication normally used to treat high blood pressure

wheat-free diet, since diarrhea can be caused by gluten in wheat flour

Antibiotics are used to treat urinary tract infections. The affected person may be taught to empty the bladder frequently. He or she may be advised to increase fluid intake.

Men who have erectile dysfunction may be treated with medication. Sometimes a penile implant is recommended. Counseling may be helpful to reduce stress.

What are the side effects of the treatments?

Antibiotics and other medications may cause stomach upset or allergic reactions.

What happens after treatment for the disease?

Good control of blood glucose levels is important. It can help prevent the onset and progression of neuropathy. Once sensation is impaired to an area, the person will need to be careful to avoid injury. Good diabetic foot care, for example, is especially important if the feet are numb.

How is the disease monitored?

The individual and his or her healthcare provider can monitor diabetic neuropathy. Repeat electromyography and nerve conduction velocity studies may be helpful. Any new or worsening symptoms should be reported to the healthcare provider.