Although consumers are now more aware of the fallibility of many kinds of treatments given by the medical profession, medical testing still enjoys a high degree of public trust. Ostensibly, medical tests are designed to assist the clinical judgement of the doctor by accurately confirming the diagnosis of hidden problems, however in practice few tests reach this ideal. There can also be dangers associated with many medical tests, either from the technique used or human error and improper usage. The aim of this book is to open up medical testing to general discussion and clarify the gap between what medical tests are expected and assumed to do, and their actual value to the patient. The authors hope that, with better informed consumers, testing will undergo a critical evaluation so that fewer expensive and sometimes dangerous tests will be performed.