An introduction discusses the incidence of pressure ulcers and their enormous cost, both monetarily and in terms of human suffering. The program then discusses principles of pressure, shear, and friction; illustrates how they occur in the healthcare setting; and describes the type of tissue damage they inflict. It also describes staging of pressure ulcers, cites factors that place a patient at risk for developing pressure ulcers, and concludes with a discussion of commonly used assessment tools.