Abstract
The principles of etiology and natural history of disease are essential to recognizing opportunities for prevention across the illness spectrum. They have a bearing on how illness is experienced, how differently it can be perceived at the time of first contact with the health system, and how it may appear at later stages. Opportunities for prevention arise at every stage in the process, and three main levels are described: primary, secondary, and tertiary. Prevention strategies include health promotion focused on determinants, clinical prevention to reduce modifiable risk factors, case finding, screening, and addressing functional outcomes relevant to quality of life; the importance of preventing errors is also recognized. The distinction between incidence effects and treatment effects of prevention is explored. This review also examines the differing roles of language in health science and public communication, aspects of disease classification, related issues in patient-centered care, the prevention paradox, and integrated models of disease prevention.