Removal of part or all of a body part that is enclosed by skin. Amputation can occur at an accident site, the scene of an animal attack, or a battlefield. Amputation is also performed as a surgical procedure. It is typically performed to prevent the spread of gangrene as a complication of frostbite, injury, diabetes, arteriosclerosis, or any other illness that impairs blood circulation. It is also performed to prevent the spread of bone cancer and to curtail loss of blood and infection in a person who has suffered severe, irreparable damage to a limb. When performing an amputation, surgeons generally cut above the diseased or injured area so that a portion of healthy tissue remains to cushion bone. Sometimes the location of a cut may depend in part on its suitability to be fitted with an artificial limb, or prosthesis.