This book is a rapid reference guide for all levels of medical staff working in emergency and acute care settings, but may also benefit nursing professionals and medical students. In this book, the readers will find diagnostic checklists, organised according to potential emergency presentations and classified under body systems, including atypical presentations, lists of differential diagnoses and guidance to pattern recognition. The book aims to help the reader achieve the correct diagnosis in an emergency setting, which continues to remain a challenge, given the variety of potential clinical presentations. Diagnostic failure is the largest reason for delays in provision of appropriate treatment and the largest source of clinical complaints and untoward incidents.