Differential Diagnosis of Normal Anion Gap Metabolic Acidosis 

Normal anion gap metabolic acidosis 

Normal anion gap metabolic acidosis occurs due to loss of hydrogen bicarbonate ions or increase in hydrogen ions excretion. The causes of normal anion gap metabolic acidosis / differential diagnosis of normal anion gap metabolic acidosis are :

-renal tubular acidosis type 1, 2 and 4
-ingestion of ammonium chloride 
-diarrhea
-intestinal fistula
-pancreatic fistula
-biliary fistula
-ureterosigmoidostomy
-ileostomy
-hyperparathyroidism
-acetazolamide 
-heavy metals or drug related renal tubular damage.