Book excerpt: Designed for quick reference, this pocket manual contains algorithms for the diagnosis of 227 symptoms and signs. The algorithms will aid the busy clinician in organizing the approach to diagnosis and performing a cost-effective workup. Symptoms and signs are arranged alphabetically. For each symptom or sign, the list of diagnostic possibilities is organized into an algorithm that shows, at a glance, what historical or clinical data to look for. Dr. Collins then explains which tests to order and when to refer the patient to a specialist. This edition includes new diagnostic tests and algorithms for differential diagnosis of abnormal routine laboratory tests.