The contribution of psychologists to the prevention of somatic disorders, and to the diagnosis or assessment, treatment and rehabilitation of patients with somatic illness, has grown very rapidly in the past decade. Behavioural Medicine is the encompassing term applied to inter-disciplinary research and patient care on this subject matter. In this book, the application of behavioural medicine is illustrated with regard to 16 somatic disorders. The disorders have been selected on the basis of their high prevalence and their relevance for health professionals. In each chapter, epidemiological aspects, the clinical picture, behavioural assessment and treatment methods with regard to the somatic illnesses or disorders, are presented. Three chapters about theoretical aspects of behavioural medicine introduce these chapters.