Diabetic neuropathy, or nerve damage caused by diabetes, is one of the most common known causes of neuropathy. High blood sugar (glucose) can injure nerves throughout your body. Diabetic neuropathy most often damages nerves in your legs and feet, problems with your digestive system, urinary tract, blood vessels and heart. It is one of many complications associated with diabetes, with nearly 60 percent of diabetics having some form of nerve damage. It is a progressive disease that can involve loss of sensation, as well as pain and weakness, in the feet and sometimes in the hands. Peripheral neuropathy may be more prevalent in people who have difficulty managing their blood sugar levels, have high blood pressure, are overweight, and are over 40 years old. A clinical examination may identify early signs of neuropathy in diabetics without symptoms.
The first sign of diabetic neuropathy is usually numbness, tingling or pain in the feet, legs or hands. Over a period of several years, the neuropathy may lead to muscle weakness in the feet and a loss of reflexes, especially around the ankle. As the nerve damage increases, the loss of sensation in the feet can reduce a person's ability to detect temperature or to notice pain. Because the person can no longer notice when his/her feet become injured, people with diabetic neuropathy are more likely to develop foot problems such as skin lesions and ulcers that may become infected.
Diabetic neuropathy may suddenly flare up and affect a specific nerve or group of nerves. When this occurs, the result may be weakness and muscle atrophy in various parts of the body, such as involvement of the eye muscles or eyelid (e.g., causing double vision or a drooping eyelid) or thigh muscles. Alternatively, neuropathy caused by diabetes may slowly progress over time. It also can interfere with the normal functioning of the digestive system and sexual organs.