Search for the #humanfactors tag in Twitter and the majority of posts relate to health care. The awareness of human factors issues in health care has grown in importance, largely as a response to patient safety concerns. The Seven steps to patient safety report by the National Patient Safety Agency (NPSA) (2004) identified human factors as something that patient safety champions and risk experts should be trained in, but without defining what it is or what level of training is required. In the National Quality Board (NQB) (2013) study, Human factors in healthcare : a concordat from the National Quality Board, major UK health care organisations came together to support the NHS, stating : 'We, the undersigned, believe that a wider understanding of Human Factors principles and practices will contribute significantly to improving the quality (effectiveness, experience and safety) of care for patients.'(NQB 2013:5) Yet the question 'What is 'human factors'?' is still regularly asked in health care settings. In order to adress this question, the autors will provide some definitions of, and describe some of the areas covered by, human factors, offer exemples from a health care context, and suggest some further reading.