On the first day of summer football practice, all players were required to have a physical. Each student was handed a plastic cup and directed to the rest room. "Please provide me with a sample," the physician requested. Most of the athletes had no idea how much could be learned about their health and behavior from a urine sample.

Immediately after handing over their samples, Philip and Seth were sent home and told to drink plenty of water before their next practice and to submit new samples then. The next day, Andrew was told to see his family physician because he could have diabetes. Several days later, another student was dropped from the team for violating the school's antidrug policy. How was all of this information gained from a urine sample? Look for clues throughout the chapter to help you discover what can be learned about the body by simply examining what leaves it. Then, solve the mystery.