Flip a switch and the lights go on. Turn the tap and you can get a cold glass of water. Give a sample of blood or urine and you get information about your health. That’s how lab tests have worked until recently. Except for the relationship you have with the person who takes the sample from you, it is rare that you get a glimpse at the many people involved in generating a valid result. Nor do you get much opportunity to learn what happens after the specimen, or test sample, disappears from view. As labs take on an increasingly prominent role in health care understanding what happens behind the scenes is almost as important as knowing how to interpret your test results. The articles listed to the left have been prepared to give you a better sense of the lab and how it functions.