Disease prevention (e.g. seat belts) involves specific interventions aimed at avoiding contact with disease producing risk factors or, where this is not possible, treatment aimed at minimising the harmful consequences of the disease process. It is commonly divided into three levels: primary, secondary, and tertiary prevention.
Preventing exposure to risk factors or enhancing individual resistance to risk factors, to prevent the onset of disease, by altering the environment etc.
Includes immunisation, promoting healthy lifestyles to people who are not (yet) ill…
Identifying and treating precursor conditions before they lead to overt disease, and early treatment of established disease. Aims to halt the progression of a disease, ideally in asymptomatic individuals. Often involves screening to identify pre-morbid conditions or sub-clinical disease.
Includes prevention of strokes by treating hypertension; cervical screening; mammography screening; screening children for CHD, undescended testes…
The prevention or reduction of mortality, morbidity, complications, disabilities, etc. (“Burden of disease”).
Includes rehabilitation after stroke; diabetes care.
Note that secondary prevention of diabetic retinopathy is tertiary prevention of diabetes!