Chronic ulcers are due to many reasons, but the main one is poor perfusion of the surrounding tissue. The most common clinical symptoms are vascular problems especially in the lower limbs, and some superficial injury. Chronic ulcers may develop in any part of the body, on skin that has undergone radiotherapy or after extended burn healing. Chronic infection of an underlying bone often leads to fistulas and chronic ulcer. Chronic ulcers may also develop from microcirculation problems (diabetes, etc).