How can diabetes hurt my feet?

High blood glucose from diabetes causes two problems that can hurt your feet:

Nerve damage. One problem is damage to nerves in your legs and feet. With damaged nerves, you might not feel pain, heat, or cold in your legs and feet. A sore or cut on your foot may get worse because you do not know it is there. This lack of feeling is caused by nerve damage, also called diabetic neuropathy (noo-ROP-uh-thee). Nerve damage can lead to a sore or an infection.

Poor blood flow. The second problem happens when not enough blood flows to your legs and feet. Poor blood flow makes it hard for a sore or infection to heal. This problem is called peripheral (puh-RIF-ur-uhl) vascular disease, also called PVD. Smoking when you have diabetes makes blood flow problems much worse.
These two problems can work together to cause a foot problem.

For example, you get a blister from shoes that do not fit. You do not feel the pain from the blister because you have nerve damage in your foot. Next, the blister gets infected. If blood glucose is high, the extra glucose feeds the germs. Germs grow and the infection gets worse. Poor blood flow to your legs and feet can slow down healing. Once in a while a bad infection never heals. The infection might cause gangrene (GANG-green). If a person has gangrene, the skin and tissue around the sore die. The area becomes black and smelly.

To keep gangrene from spreading, a doctor may have to do surgery to cut off a toe, foot, or part of a leg. Cutting off a body part is called an amputation (AM-pyoo-TAY-shuhn).

Skin Problems in Diabetes

If you have diabetes, it’s important to be aware of potentially serious skin problems related to diabetes and see your doctor before the problem gets out of control. In most cases, skin problems in diabetes can be managed with early diagnosis and treatment.

Diabetes Skin Problems
Scleroderma diabeticorum: While rare, this skin problem affects people with type 2 diabetes, causing a thickening of the skin on the back of the neck and upper back. The treatment is to bring your blood glucose level under control. Lotions and moisturizers may help soften skin.
Vitiligo: Vitiligo, a skin problem more commonly associated with type 1 diabetes than type 2 diabetes, affects skin coloration. With vitiligo, the special cells that make pigment (the substance that controls skin color) are destroyed, resulting in patches of discolored skin. Vitiligo often affects the chest and abdomen, but may be found on the face around the mouth, nostrils and eyes. Current treatment options for vitiligo include topical steroids and micropigmentation (tattooing). If you have vitiligo, you should use sunscreen with a SPF of 15 or higher to prevent sunburn on the discolored skin.

Skin Problems Linked to Diabetes and Insulin Resistance
Acanthosis nigricans. This is a skin problem that results in the darkening and thickening of certain areas of the skin especially in the skin folds. The skin becomes tan or brown and is sometimes slightly raised and described as velvety. Most often the condition, which typically looks like a small wart, appears on the sides or back of the neck, the armpits, under the breast, and groin. Occasionally the top of the knuckles will have a particularly unusual appearance. Acanthosis nigricans usually strikes people who are very overweight. While there is no cure for acanthosis nigricans, losing weight may improve the skin condition. Acanthosis nigricans usually precedes diabetes and is considered to be a marker for the disease. There are other health conditions that also are known to cause acanthosis of the skin and these include acromegaly and Cushing syndromes. It is thought that this health condition is a skin manifestation of insulin resistance.