Pressure ulcers usually develop over an area of bony prominence and, while they are a localised injury to the skin and/or underlying tissue, they can vary in severity from patches of discoloured skin to open wounds that expose the underlying bone or muscle. Any client can develop a pressure ulcer, but some factors increase risk, especially those that result in interface pressure, shear, friction and moisture. Pressure ulcers are a preventable and costly occurrence that act as a key indicator of the quality and experience of client care.