What is a "screening" exam? A screening examination is one that is done on asymptomatic patients in order to "catch" a process early enough to intervene and hopefully avoid complications in the future. In the non-medical world, you might check your gutters every 6 months to make sure leaves haven't built up or check your oil with a dipstick at the gas station every month. In your personal life, you may remember being screened for scoliosis or for your vision. Screening exams are important for several types of conditions, and large scientific trials have often proved their validity.