This is a quick reference guide to the selection and interpretation of more than 450 commonly used diagnostic tests. It covers: basic principles of diagnostic testing, common blood, urine and cerebrospinal fluid laboratory tests, therapeutic drug monitoring, microbiologic test selection and interpretation and diagnostic imaging tests by body system, electrocardiography, and differential diagnosis tables & algorithms; and tests used in internal medicine, pediatrics, surgery, neurology and obstetrics and gynecology. It includes: costs and risks of diagnostic tests; evidence-based information; diseases associated with abnormal test results, including test sensitivities; full literature citations with PubMed (PMID) numbers included for each reference; more than 24 NEW clinical laboratory test entries, 6 NEW differential diagnosis tables; 5 NEW diagnostic algorithms; and, NEW sections on point-of-care testing, provider-performed microscopy, pharmacogenetic testing, and diagnostic echocardiography.