In people with diabetes, nerve damage leads to dry, cracked, fissured, and calloused feet. These cracks can become infected and enlarge. Infection can cause damage to blood vessels in the foot, making wound healing difficult or prolonged. Diabetic foot stages are as follows:

Stage 0: Healthy skin
Stage 1: Superficial ulcer
Stage 2: Deep ulcer
Stage 3: Ulcer with bone involvement
Stage 4: Gangrene of the forefoot or toes
Stage 5: Gangrene of the foot