Disease Prevention Checklist

Why do I need screenings if I don't feel sick?

Changes are always occurring in our bodies, especially as we age. Although most are harmless, a few have the potential for harm. Some changes are related to age itself, and some involve lifestyle—smoking, alcohol and drug abuse, lack of exercise, a poor diet, and stress, for example. Screening tests search through seemingly healthy people, looking for those who might have harmful conditions that are still in an early stage, before they become serious problems. This means before you have symptoms serious enough to motivate you to see a doctor (when you are "asymptomatic," or before symptoms are said to become "clinical"). When a screening test reveals the possibility of a harmful condition, the usual procedure is to confirm the existence of the condition with follow-up tests and then to do something active about the condition—change lifestyle habits, take medication, or have surgery. In theory, the value of screening tests is that, in the long run, there will be less illness and death from the condition in question than if the screening test had not been given. However, figuring this out is not as simple as it seems.