Epidemiology involves the study of the distribution and determinants of health in a given population, and the subsequent application of this study to improve outcomes. This book introduces major topics in this field, and where applicable, illustrated by tables and figures from Norwegian and Swedish studies. The first twelve chapters concern epidemiologic methods, including discussion of study designs and bias, together with an overview of vital statistics and a discussion on causality. The final eight chapters discuss changes in health more generally (or the epidemiologic transition), prevention, an introduction to genetic epidemiology, infectious disease, reporting observational studies, and assessing new information. The book is aimed at students in medical school, as well as public health and other health sciences students at the Bachelor and Master's level. Anmeldelse fra Tidsskriftet for Den norske legeforening nr. 22-2015