Pressure on the skin blocks the blood supply. When skin is deprived of nutrients and oxygen for too long, the skin starts to break down, the tissue dies and a pressure ulcer forms. The first sign of a pressure ulcer is redness on the skin. Persons may get pressure ulcers after as little as 1-2 hours. Pressure ulcers form where bone causes the greatest force on the skin and tissue.
Pressure ulcers can also form behind the knees, for people confined to chairs or wheelchairs.
These steps can also keep pressure ulcers from getting worse. Take care of your skin Inspect skin at least once a day. Pay special attention to any reddened areas. Keep the skin clean and dry. Use a soft cloth to clean your skin and wash it as soon as it is soiled.