Harwood-Nuss' Clinical Practice of Emergency Medicine presents a clinically focused and evidence-based summary of emergency medicine. Chapters are templated to include the clinical presentation, differential diagnosis, evaluation, management and disposition, with highlighted critical interventions and common pitfalls. Management and disposition are especially critical in the emergency department, and their emphasis is unique to Harwood-Nuss. Often, a diagnosis can not be made, given the constraints of an ED evaluation; thus, effecive management of the patient, with or without a confirmed diagnosis, is key. Also distinct to Harwood-Nuss is the High-Risk Chief Complaints section, which covers the key presentations in the ED: chest pain, abdominal pain, shortness of breath, altered mental status. When patients present in the ED, they don't present with a known diagnosis; this chapter walks the physician through possible differential diagnoses and the evaluation and management of these patients so that they can be stabilized and treated quickly and effectively.