Close up of a bedsore on an elderly woman's buttock. A bedsore (also called a decubitus ulcer or pressure sore) is an ulcerated area of skin caused by irritation and continuous pressure on a part of the body. Bedridden, elderly patients (especially those unconscious) are particulary vulnerable. Healing is hampered by a reduced blood supply and diligent nursing care (cleansing, repositioning) is needed to prevent local gangrene occurring. This photograph is the first in a series of five taken over a six month period that shows partial healing of the ulcer. Photo taken 13/01/88