preventives

Preventives are actions, practices, and policies designed to reduce the likelihood of disease, injury, or disability before they occur. They encompass biomedical, behavioral, and environmental measures and can be implemented at the level of individuals, communities, and health systems.

Health preventive strategy is often described in levels of prevention. Primary prevention aims to prevent disease from developing, through vaccination, prophylaxis, health education, and environmental improvements. Secondary prevention seeks to detect disease at an early stage to prevent progression, through screening tests and early treatment. Tertiary prevention reduces complications and disability after a disease has been diagnosed, by rehabilitation and disease management. Some frameworks also include primordial or quaternary prevention, focusing on reducing risk factor emergence and avoiding unnecessary interventions, respectively.

Preventives are delivered by clinicians, public health programs, schools, workplaces, and governments. Examples include immunization programs, screening campaigns, fluoride varnish in dental care, sealants, seat belt and helmet laws, tobacco control, and policies that promote clean air and safe drinking water. Individual actions such as regular exercise, healthy eating, stress management, and vaccination all contribute to preventive goals.

Effectiveness and value of preventive measures depend on evidence, context, and equity. Challenges include ensuring access, acceptance, and adherence, managing potential harms from overdiagnosis or overtreatment, and allocating resources efficiently. When well designed and implemented, preventives can reduce illness, extend healthy life years, and lower health care costs.