Diabetic neuropathy is nerve damage caused by diabetes. It can occur anywhere in the body, but the most common areas are the feet, toes, hands and arms. Diabetic neuropathy of the feet is caused by high blood glucose levels, which can damage blood vessels and nerves over time. Other factors can contribute to diabetic neuropathy of the feet, including the duration of diabetes, high levels of blood fat and low insulin levels. Diabetic neuropathy of the feet is also called peripheral neuropathy, distal symmetric neuropathy and sensorimotor neuropathy.
Experts estimate that as much as 70 percent of people with diabetes have some type of neuropathy. It is more common in people who have had diabetes for 25 years or longer. Prolonged high glucose levels is the primary cause of diabetic neuropathy, because excessive blood glucose prevents the transmission of signals from the nerves. Additionally, high glucose levels damage the walls of blood vessels, including those feeding the nerves. Damaged capillaries starve the nerves of oxygen, impairing their ability to function.
Nerve inflammation from autoimmune disorders and mechanical injury to the nerves, such as carpal tunnel syndrome, also increase the risk of diabetic neuropathy. Disorders that damage the blood vessels leading to the nerves also cause neuropathy. Lifestyle factors such as smoking and excessive alcohol use as well as a genetic predisposition to nerve damage are important factors.
The symptoms of peripheral neuropathy appear gradually over years. Early symptoms are mild and are often overlooked. The toes, feet and legs are affected before the hands, arms or other areas of the body. The most common symptoms are tingling, numbness, or a prickly feeling in toes and feet. There might also be insensitivity to pain, such as when a toe is pricked with a pin.
Other symptoms include sharp pains or cramps, loss of balance and coordination, extreme sensitivity to the slightest touch, weakness and dizziness when standing. There might be changes in gait because of numbness or foot deformities such as hammertoes. Blisters and sores can develop on the feet because the sensation of pressure or rubbing can no longer be felt. Symptoms might worsen at night.
People who have diabetic neuropathy of the feet must take particular care of their feet. Feet should be thoroughly washed and dried daily and inspected for cuts, blisters or sores. The feet should be examined at least annually by a medical professional for signs of neuropathy. All foot infections must be treated promptly. Infections can easily travel to the bone, requiring amputation.