The first edition of Harrison's Principles of Internal Medicine was published more than half a century ago. Over the decades, this textbook has evolved to reflect the continuing advances in the field of internal medicine and to meet the growing information base required of medical students and clinical practitioners. The users of this sixteenth edition of Harrison's will not even have to open the volume to see that it marks a transition point in the book's history. The new cover is only the most obvious indication of a new direction for Harrison's.
In shaping and revising this new version, the Editors have committed themselves to making the textbook as useful as possible to students and practitioners coping with the demands of modern medicine. The growth of evidence-based medicine, the prominence of managed care, and the explosion of information in fundamental areas such as the genetics of disease are only three of the many factors that make these demands different from those faced by physicians only a decade ago. Just as the cover retains key elements of the classic book, the content of the sixteenth edition retains the essential facts that remain clinically useful and important. However, through modifications in both its format and its content, the new Harrison's addresses the changing needs of its readers.