This unit considers two ideas: that health is an ever-present factor in our lives, and that health is something difficult to define. But how can we say that health is everywhere if it is so mysterious? How do we recognise health if it so difficult to define? There are no easy answers to these questions! In this unit we explore this paradox, not just because it is a fascinating dilemma but because understanding health in all its multifaceted complexity is a prerequisite to working for health in imaginative, creative and useful ways, in both our private and our public lives. This study unit is just one of many that can be found on LearningSpace, part of OpenLearn, a collection of open educational resources from The Open University. Published in ePub 2.0.1 format, some feature such as audio, video and linked PDF are not supported by all ePub readers.