Book excerpt: Physician Assistant Review, Fourth Edition provides a comprehensive review for students and practicing physician assistants preparing for the Certification (PANCE) and Recertification (PANRE) examinations. Nineteen sections organized by body system describe common diseases in a consistent format: etiology, pathology, clinical features, diagnostic studies, and management. Access to a companion Website offers over 1,000 Board-format questions, which can be taken in Study Mode or Test Mode, and a 360-question comprehensive exam. Complete explanations of both correct and incorrect answer choices are provided to help you better understand your area of weakness to better focus your studying. New for this edition: A new chapter, Preventive Medicine, has been added Each chapter has been updated to reflect the latest standards of care and revisions based on our readers' feedback Expanded online, updated test bank with rationales for the correct and incorrect answers to help focus your studying Team of test-item reviewers have reviewed the test questions to ensure you are getting the best quality questions