This book is written for medical students and house officers working on the wards, in the intensive care unit, and in the emergency room. It is intended for use by all whose work involves the daily evaluation and management of medical emergencies. The material is a compilation of information gained from our personal experiences in clinical practice, from participation in professional meet­ ings and conferences, and from searching the medical literature. The introductory chapters in Part I form a foundation that is devel­ oped in the subsequent parts where specific topics are discussed. When possible, we have simplified complex approaches to diagnosis and man­ agement by formulating algorithms and handy reference tables. Since this is a handbook and not a textbook, we have limited our discussion of pathogenesis and pathophysiology in order to concentrate on practical aspects and specific details that are useful in the diagnosis and management of pulmonary emergencies. Our aim is to alert young physicians to common pulmonary emergencies and guide them through their initial management.