Over the past few years in the UK, there has been an increasing focus on the prevention of pressure ulcers (PUs) because they have come to be recognised by the Department of Health as a preventable harm (Stephen-Haynes, 2011). Targets for their reduction have been advised nationally via Safety Thermometer (Health and Social Care information Centre, 2013), and set locally by commissioners. This focus on the prevention of PUs has been welcomed by tissue viability nurses, who have persistently strived to introduce strategies that will prevent PU development. However, it has also created a need for clarity and deeper understanding around what is – and what is not – a PU as well as a need to define when PU development may be unavoidable.