High blood sugar from diabetes causes two problems that can hurt your feet:
These two problems can work together to cause a foot problem.

Make sure you wear shoes that fit well.
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 sugar is high, the extra sugar 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 (amp-yoo-TAY-shun).