This new edition has precisely the same ethos but has been improved greatly by the addition of new members to the writing team. We have enlisted the help of experts in cardiology, gastroenterology, rheumatology and immunology. The new authors have rewritten their respective chapters entirely and, as a result, the book is much enhanced. Other chapters have also seen major rewrites and the addition of many new graphics; in fact, the number of illustrations has almost doubled. This helps break up the text and also improves the readability of each chapter. With so much medical information available on the Internet, most chapters contain URLs for websites that provide full guidelines and other information which should be of value to the reader.