Explore the differential diagnosis of normal anion gap metabolic acidosis in this comprehensive lecture. Delve into renal tubular acidosis, examining its various types and etiologies. Learn about other causes including diarrhea, saline infusion, hyperkalemia, kidney failure, and ureteral diversion. Understand the pathogenesis of Type 4 RTA and compare different RTA types. Discover the significance of the urine anion gap and develop a systematic approach to diagnosing normal gap metabolic acidosis. Gain valuable insights into interpreting arterial blood gas results and enhancing your clinical decision-making skills in acid-base disorders.