Medicine has come a long way since ancient times, when diagnoses were made by feeling patients' heads or gazing into their eyes.
Doctors can now look directly at everything from arteries to intestines.
But, let's face it, some of these modern medical tests are uncomfortable, even painful. HealthWeek's Lauren Scott looks at efforts to move medical screening into the 21st Century. While these tests are valuable, they are often grueling. Cecelia Roberts needed to be checked for colon cancer so her doctor sent her for a colonoscopy - a common test for examining the colon. However, it can be an uncomfortable test, it's invasive, and it requires sedation.