ABSTRACT
Stages of disease: Susceptibility = behavioral > genetic = risk factors Presymptomatic = pathogenesis = premalignant (premorbid) Clinical disease = morphological extent. Example: cancer = tumor, nodes, metastases TNM classication. Functional classication = Example: New York Heart Association Classication (NYHA I-IV) of impairment by cardiovascular disease Disability = residual = short (Acute) or long term (Chronic)
Susceptibility Presymptomatic Clinical disease Disability
Primary: Primary prevention of disease by vaccination or behavioral change (smoking cessation). Secondary: Screening for presymptomatic disease to prevent exacerbations and complications. Tertiary: Treatment of clinical disease. Quaternary: Rehabilitation to restore functional capability and quality of life.
