Diabetic Neuropathies: The Nerve Damage of Diabetes
On this page:

Causes
Symptoms
Types of Diabetic Neuropathy
Neuropathy Affects Nerves Throughout the Body
Peripheral Neuropathy
Autonomic Neuropathy
Proximal Neuropathy
Focal Neuropathy
Preventing Diabetic Neuropathy
Diagnosis
Treatment
Points to Remember
Hope Through Research
For More Information
Diabetic neuropathies are a family of nerve disorders caused by diabetes. People with diabetes can, over time, have damage to nerves throughout the body. Neuropathies lead to numbness and sometimes pain and weakness in the hands, arms, feet, and legs. Problems may also occur in every organ system, including the digestive tract, heart, and sex organs. People with diabetes can develop nerve problems at any time, but the longer a person has diabetes, the greater the risk.

An estimated 50 percent of those with diabetes have some form of neuropathy, but not all with neuropathy have symptoms. The highest rates of neuropathy are among people who have had the disease for at least 25 years.

Diabetic neuropathy also appears to be more common in people who have had problems controlling their blood glucose levels, in those with high levels of blood fat and blood pressure, in overweight people, and in people over the age of 40. The most common type is peripheral neuropathy, also called distal symmetric neuropathy, which affects the arms and legs.

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Causes
The causes are probably different for different varieties of diabetic neuropathy. Researchers are studying the effect of glucose on nerves to find out exactly how prolonged exposure to high glucose causes neuropathy. Nerve damage is likely due to a combination of factors:

metabolic factors, such as high blood glucose, long duration of diabetes, possibly low levels of insulin, and abnormal blood fat levels


neurovascular factors, leading to damage to the blood vessels that carry oxygen and nutrients to the nerves


autoimmune factors that cause inflammation in nerves

mechanical injury to nerves, such as carpal tunnel syndrome


inherited traits that increase susceptibility to nerve disease


lifestyle factors such as smoking or alcohol use
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Symptoms
Symptoms depend on the type of neuropathy and which nerves are affected. Some people have no symptoms at all. For others, numbness, tingling, or pain in the feet is often the first sign. A person can experience both pain and numbness. Often, symptoms are minor at first, and since most nerve damage occurs over several years, mild cases may go unnoticed for a long time. Symptoms may involve the sensory or motor nervous system, as well as the involuntary (autonomic) nervous system. In some people, mainly those with focal neuropathy, the onset of pain may be sudden and severe.