There is a geography to premature death in Britain. This geography is largely the mirror image of the geography of good health. The concept of health is very difficult to define, and even more difficult to measure. For example, the World Health Organisation (1948) defined health as ‘a state of complete physical, mental and social well-being and not merely the absence of disease’. Because good health is so difficult to define and measure, geographers often use the map of premature death-a much more easily definable and measurable outcome-as a proxy for a map of ill health. In this chapter we shall introduce you to the geography of good and poor health and how health can be counted and the factors behind health measured. We shall show you maps of areas of good and poor health for different groups of the population and describe how and why these maps have changed over the last fifty years. We shall also explain how the geography of health in Britain has been changing over recent decades. These patterns and changes will be illustrated by showing you how you can estimate your own life expectancy.