Patient-centred medicine has come out of the increasing importance of patients’ voices in disease management. As part of this, health related quality of life (HR-QoL) has become an important part of assessing treatment outcome and the quality of patient management. In this article, I discuss health as one of the determinants of a good quality of life and how to interpret and present HR-QoL measures and thereby place them in a clinical context. Key issues covered include the theoretical HR-QoL models underlying HRQoL measures, how the measures are constructed, how they work, and how to interpret the scores they generate.