Diabetic Neuropathy is a nerve disorder caused by diabetes. People who had diabetes for years may experience numbness and sometimes pain in their hands, feet and legs. Nerve damage caused by diabetes can also lead to problems with indigestion, diarrhea or constipation, dizziness, bladder infections, and impotence. In some cases, damaged nerves can strike suddenly, causing pain, weakness, and weight loss. Depression may follow. While some treatments are available, a great deal of research still needs to be done to understand how diabetes affects the nerves and to find better treatments for this complication.

Nerve problems can affect anybody with diabetes, but they are most common in people who have had diabetes more than 10 years. The majority of patients with neurological impairment due to diabetes do not have symptoms such as pain or numbness. Scientists do not know how diabetic neuropathy occurs, but it is likely that several factors come into play. High blood glucose causes chemical changes in nerves, impairing their ability to transmit nerve signals. High blood glucose also damages blood vessels that carry oxygen and nutrients to the nerves. Also, inherited factors probably unrelated to diabetes may make some people more susceptible to nerve disease than others. The study of the chemical changes that happen to nerves exposed to high blood glucose is a very active area of research. A normal substance called aldose reductase converts glucose to a type of sugar alcohol called sorbitol. Scientists have found that when tissues have a high level of glucose, sorbitol builds up and apparently damages the membranes lining body tissues.

Studies have shown that proteins age more quickly when exposed to high glucose. This has the effect of weakening certain connective proteins called collagens, which line and support nerve tissue. While these changes occur with normal aging, high blood glucose speeds up the damage.

The symptoms of diabetic neuropathy vary a great deal. Some people notice no symptoms, while others are disabled by severe problems. Neuropathy may cause both pain and insensitivity to pain the same person. Often, symptoms are slight at first, and since most nerve damage occurs over years, mild cases may go unnoticed for a long time. In some people, though, mainly those afflicted by mononeuropathy, the onset of pain may be sudden and severe.

A doctor diagnoses neuropathy from symptoms and a physical exam. During the exam, the doctor may check muscle strength, reflexes, and sensitivity to position, vibration, temperature, and light touch. Sometimes special tests are used to pinpoint the cause of symptoms and suggest treatment:

* Ultrasound employs sound waves too high to hear, which produce an image showing how well the bladder and other parts of the urinary tract are functioning.

* Nerve condition studies check the flow of electrical current through a nerve. With this test, an image of the nerve impulse is projected on a screen as it transmits an electrical impulse. Impulses that seem slower or weaker than usual indicate possible damage to the nerve.

*Electromyography (EMG) is used to see how well muscles respond to electrical impulses transmitted by the nerves nearby.

*Nerve biopsy involves removing a sample of nerve tissue, which is examined for damage. This test is mot often used in research settings.

Treatment aims at relieving discomfort and preventing further tissue damage. The first step is to bring blood sugar under control by diet and oral drugs or insulin injections, if needed. Although the symptoms can sometimes worsen as blood sugar is brought under control with intensive treatment, careful long-term monitoring of blood sugar helps reverse the pain or loss of sensation that neuropathy can cause. Good control of blood sugar with diet and, if necessary, drug therapy may also help prevent or delay the onset of further problems.

A number of medications are used to relieve the symptoms of diabetic neuropathy: An analgesic such as aspirin or acetaminophen, an anti-inflammatory drug containing ibuprofen, antidepressant medications such as amitriptyline, sometimes used with fluphenazine, or nerve medications such as carbamazepine or phenytoin sodium. Codeine is sometimes prescribed for short-term use to relieve severe pain. Your doctor may prescribe a therapy known as transcultaneous electronic nerve stimulation (TENS). For patients with mild symptoms of slow stomach emptying, doctors suggest eating small, frequent meals and avoiding fats and less fibers.

Another important part of treatment involves special care of the feet, which are especially prone to problems.