Medical screening is a procedure that is undertaken before an individual experiences any signs or symptoms of a particular disease. Screening tests can be applied rapidly in an effort to sort out apparently well persons who probably have a specific health condition from those who probably do not. Screening helps identify disease and other health conditions early, when they are easier to treat and may be curable. Identifying disease early greatly improves prognosis. Early detection of disease through screening can lead to a greater range of treatment options, less extensive treatments, better treatment outcomes and improved cost-effectiveness. Screening is an essential part of preventative care.