A pressure ulcer or bed sore is an injury to the skin caused by constant pressure over a bony area which reduces the blood supply to the area. Pressure can be caused by the resident lying too long in one position or by tubing or devices that press on the skin. Pressure ulcers can be dangerous and painful for a resident, in part because broken skin can introduce infection into the body. If untreated, pressure ulcers can deepen to the point where they expose the bone. Deeper ulcers may be hard to heal or may not heal at all. Sometimes, pressure ulcers can lead to serious medical complications and even death. Even if pressure ulcers heal, the skin never returns to normal and will be at higher risk for future pressure ulcers.