Gangrene is caused by a loss of blood supply to part of the body – usually due to poor circulation or a bacterial infection from an open sore or ulcer. People with diabetes or other conditions that affect circulation are more prone to developing this condition. Some symptoms of gangrene include feet or leg pain, a decrease in skin temperature and changes in skin color. Gangrene is a very serious condition that can spread throughout the body, especially if it is caused by an infection that is left untreated. Treatment usually includes the removal of the infected or dead tissue and oxygen therapy and antibiotics to stop the infection. If the gangrene has progressed to a certain level, then amputation may be required to prevent it from spreading to the rest of the body.