Prevention

Prevention refers to actions aimed at reducing the likelihood, severity, or consequences of health problems, injuries, and other adverse events. It encompasses individual behaviors, community interventions, and policy measures designed to interrupt risk processes before they lead to harm. Prevention can be applied across health, safety, environment, and social spheres.

In public health and medicine, prevention is commonly categorized into primary, secondary, and tertiary levels. Primary prevention aims to prevent the onset of disease or injury, through vaccination, hygiene, health education, and environmental controls. Secondary prevention seeks to detect and treat problems early to halt progression, through screening and early intervention. Tertiary prevention focuses on reducing damage and disability once a condition has developed, through rehabilitation and disease management.

Prevention strategies include individual behavior changes, community programs, and policy or structural measures. Examples include immunization programs, nutrition and physical activity guidance, safety laws (seat belts, helmet use), sanitation and housing improvements, regulation of pollutants, and crime and accident prevention initiatives. Evaluation uses outcomes like incidence, mortality, health-adjusted life years, and cost-effectiveness to determine impact.

Effective prevention often requires multi-sector collaboration, surveillance, and addressing social determinants of health. Limitations include the need for long time horizons for benefits, potential unintended consequences, ethical considerations, and disparities in access to preventive services.