👉 A bedsores are a condition in which the skin on the body of an animal or person is so damaged and painful that it can no longer be covered with clothing. Bedsores occur when blood vessels become blocked, causing tissue to absorb fluid from the surrounding tissues and cause swelling. Bedsores can appear anywhere on the body, but they are most common in the legs, back, and arms. They can also affect the skin, muscles, tendons, ligaments, and nerves.