What is the general purpose of health 'screening' tests?

Screening tests are a secondary prevention measure intended to detect disease or risk factors early, often before symptoms appear, so that earlier diagnosis and intervention become possible and outcomes can be improved. Examples include blood pressure checks and various recommended screenings appropriate to age and risk. Screening does not cure disease, immunize, or replace a full examination; an abnormal screen typically leads to further diagnostic evaluation. Understanding the early-detection purpose of screening is a standard health-promotion concept. (Specific screening recommendations and intervals change over time and should be verified against current authoritative guidelines and NCLEX prep materials.)