Internal Medicine is the backbone of clinical practice and the most extensive subject in postgraduate and international medical examinations. This book, “Internal Medicine – A Complete MD & USMLE Review,” is a comprehensive, system-based, exam-oriented textbook designed to meet the needs of MD Medicine residents, USMLE aspirants, PLAB candidates, NEXT examinees, and practicing physicians worldwide . The book is structured into 20 meticulously organized units , covering every major system in Internal Medicine, including Cardiology, Respiratory Medicine, Gastroenterology, Hepatology, Nephrology, Endocrinology, Hematology, Neurology, Rheumatology, Infectious Diseases, Oncology, Geriatrics, Emergency & Critical Care, Nutrition, Dermatology, Psychiatry, Immunology, Preventive Medicine, and Medical Ethics .