Internal Medicine is designed to provide the busy clinician with precisely the information needed where and when it is needed. The Associate Editors and contributors are internationally recognized authorities, and they have organized the content specifically so as to convey the essentials necessary for diagnosis, differential diagnosis, management, treatment and follow-up. Many topics start with a “What To Do First” heading which brings the collective experience and guidance of top experts to bear on the “up front” considerations the clinician must face. We are excited about Internal Medicine and hope you share our view that it is an essential resource, particularly in our current era of shortened physician-patient encounters and the need for rapid clinical decision-making.