The National Pressure Ulcer Advisory Panel has updated the definition of a pressure ulcer and the stages of pressure ulcers based on current research and expert opinion solicited from hundreds of clinicians, educators, and researchers across the country. The amount of anatomical tissue loss described with each stage has not changed. New definitions were drafted to achieve accuracy, clarity, succinctness, clinical utility, and discrimination between and among the definitions of other pressure ulcer stages and other types of wounds. Deep tissue injury was also added as a distinct pressure ulcer in this updated system.