The amount of research on the prevalence and nature of various forms of anxiety disorders, problematic health behaviors, and physical illness has significantly accumulated, yet there has been no systematic integration of the research in science and practice. Anxiety in Health Behaviors and Physical Illness is a single resource that offers theoretical perspectives and reviews of research on the link between health behaviors and physical illness to anxiety. The authors explore the idea of reciprocal relations between anxiety and health factors throughout the developmental course. Special attention is devoted to the mechanisms by which certain health factors (e.g. physical exercise) may play a role in the onset or maintenance of particular anxiety disorders.