DefinitionA pressure ulcer is an area of skin that breaks down when you stay in one position for too long without shifting your weight. This often happens if you use a wheelchair or you are bedridden, even for a short period of time (for example, after surgery or an injury). The constant pressure against the skin reduces the blood supply to that area, and the affected tissue dies.A pressure ulcer starts as reddened skin but gets progressively worse, forming a blister, then an open sore, and finally a crater. The most common places for pressure ulcers are over bony prominences (bones close to the skin) like the elbow, heels, hips, ankles, shoulders, back, and the back of the head.Alternative NamesBedsore; Decubitus ulcerCausesThese factors increase the risk for pressure ulcers:Being bedridd