Pressure injuries are caused by constant pressure on the skin and tissues.

Other things that can make pressure injuries more likely include:

• Sliding down in a bed or chair (shear force).
• Being pulled across bed sheets or other surfaces (friction).
• Not getting enough nutrition to keep your body working well (malnutrition).
• Not being able to get out of bed or walk around (immobility).
• Having a disease that affects how well blood circulates in your body, such as diabetes or peripheral arterial disease.
• Excess moisture, such as from sweat, urine, or feces. Skin that is often wet is more likely to break down and form pressure injuries.

At first, the skin may appear reddened. Or the skin may look purple or dark red. In darker skin, the color may differ from that of nearby skin. The injury may be tender and warm to the touch. It may break open or form an ulcer where fat, bone, or muscle may be visible.

A doctor can diagnose a pressure injury by examining it. In some cases, the doctor may want to do blood tests to check for infection or to see if you're getting enough protein in your diet. The doctor may also want to do a skin and wound culture or a skin biopsy.

Treatment focuses on preventing a pressure injury from getting worse and on making the skin healthy again. It may include:

• Taking pressure off the area, changing positions often, and spreading body weight evenly with special mattresses, pads, or other support.
• Keeping the wound clean and covered with a bandage. The doctor will tell you how to care for your wound. You may need to keep the wound a little moist and not let it dry out between bandage changes.
• Eating a healthy diet with enough protein.
• Having debridement. This is when the doctor removes dead tissue from the wound to promote healing.
• Having surgery. Severe pressure injuries may be treated with surgery. A tissue flap or skin graft may be needed.

Negative-pressure wound therapy, also called vacuum-assisted closure, may be used to help with healing.

Researchers continue to study these and other treatments for wounds, including electrical stimulation, hyperbaric oxygen therapy, platelet-derived growth factor, and ultrasound therapy.