This book examines the effect of social relationships on physical health. It surveys and assesses the research which shows not only that supportive relationships protect us from a multitude of mental health problems but also that the absence of supportive relationships increases the risk of dying from various diseases. The book discusses the links between social support and mortality from cardiovascular disease, cancer, and HIV/AIDS. It investigates whether social support is more effective for some individuals and within certain cultures. After evaluating existing conceptual models linking social support to health outcomes, the book offers his own broader perspective on the issue, and suggests the implications for intervention and for future research in this area.