The "medical checkup," like hot dogs and apple pie, has become an American tradition. Adolescents have checkups requested by schools, summer camps, sports teams, employers, parents, and, less frequently, themselves. At such times, a cursory chat between the teenager and health professional, followed by a quick physical examination, is unlikely to detect the most prevalent and significant health problems of young people today. The very nature of such an interaction may even serve to alienate the teenager from the health care system or provider. Alternatively, if properly focused and thorough, a checkup may not only uncover important areas of disease or dysfunction, but also should initiate a meaningful dialogue and relationship between the adolescent patient and health professional. A checkup generally occurs when an individual feels well and visits a medical professional without complaint or a checkup may be had in conjunction with medical attention to a specific problem. In either case, the primary purpose of a checkup is health assessment and screening. Health screening has been defined by the World Health Organization as ". . . the presumptive identification of unrecognized disease or defect by the application of tests, examinations, or other procedures which can be applied rapidly." The purpose of health screening is to detect a problem (or problems) before it would usually become apparent or before medical attention is sought, with the intent of initiating treatment at an earlier and more optimal time, so as to prevent or favorably alter its course and consequences. Screening is not in itself diagnostic.