A health screening examination performed on a scheduled or routine basis. The appropriate features of this examination depend on the patient’s age, gender, and sometimes health history, family history, or employment status. Adult women, for example, should have periodic examinations, including Pap smears and professional breast examinations, whereas professional pilots and truckers are screened periodically for visual impairment and hypertension, among other conditions. All adults over age 45 should be screened for diabetes mellitus. Patients with a personal history of cancer may be screened periodically for evidence of disease recurrence. For many patients, the periodic examination may include blood tests (e.g., to check levels of cholesterol and other lipids), immunological tests (e.g., health care workers are periodically screened for tuberculosis), or invasive examinations (e.g., sigmoidoscopy or colonoscopy to look for colon cancer).