Some doctors sit with you for hour-long chats, gently probing the issues, discussing all the angles. And some bosses say "you work too hard, take the week off, with pay." But for most of us, doctors are short of time, and by the time you think up the questions you want answered, your appointment"s long over. What causes chronic fatigue syndrome, can diet affect hay fever, and is there a test for hypoglycemia? That"s where Maryann Napoli comes in, with her guide to the 513 questions people most want to ask their doctors, from acne through yeast infections, and with the answers to those questions.