How can diabetes affect the feet? High blood sugars can lead to the damage of the nerves. This causes numbness of the feet. As a result you may not feel the pain and become unaware of the problem. Diabetes can also damage your blood vessels of the feet. Which leads to the poor blood supply to the feet there by delaying the wound healing process. A minor injury or a small sore may progress in ti a nonhealing ulcer. Gangrene(blackening of that part) can occur if the wound gets infected and has poor blood supply .Amputation of that part of the leg is then necessary. This situation can be avoided if we are aware of the common problems and treat them immediately. Immediately contact your doctor if a sore or other foot problem doesn’t begin to heal in one day.