conflicts of interest, and even when your doctor does not directly benefit, there are many other reasons you should be on the alert. In good faith, doctors use many treatments which do not work, and since all treatments will cause harm to some patients, doctors do harm to many people. Therefore, you must look up evidence in order to protect yourself against being harmed. Harm is usually caused by drugs but can also be caused by, for instance, infections, surgeries, Chinese herbs, electroshock, diagnostic testing, and admission to hospitals - dangerous places because of the many errors made there. This book is intended to be a self-help guide to finding the most reliable evidence about diagnostic methods and healthcare treatments. It is written for everyone, even doctors and other health professionals who, like patients, can feel lost when looking for answers to the most pertinent questions on the Internet. – Peter C. Gøtzsche