Determining the cause of a water diuresis in nonpregnant adults and adolescents with polyuria and normal serum sodium using reliable copeptin assays

Arginine vasopressin resistance was previously called nephrogenic diabetes insipidus; arginine vasopressin deficiency was previously called central diabetes insipidus.

As the diagnostic thresholds for copeptin have not been established in pregnancy, this algorithm is not intended for use in pregnant patients.

ADH: antidiuretic hormone; IV: intravenous.