Our health is determined by a complex mix of factors including income, housing and employment status, and lifestyle. There are significant inequalities in health, including life expectancy, between individuals and groups in society. So what creates those inequalities and what are the implications? This report revisits and updates some of the findings of the Marmot Review. In addition, it considers a wider set of data on a range of factors for 6,700 small areas in England to explore how and why life expectancy is changing over time.