Renal H2O loss (Uosm <700–800)

• Diuresis: osmotic (glucose, mannitol, urea), loop diuretics

• Diabetes insipidus (Nature Reviews Nephrology 2015;11:576)

ADH deficiency (central) or resistance (nephrogenic)

Central: hypothalamic or posterior pituitary disease (congenital, trauma/surgery, infiltrative/IgG4); also idiopathic, hypoxic/ischemic encephalopathy (shock, Sheehan’s syndrome), anorexia, sarcoidosis, histiocytosis, drugs: EtOH, phenytoin, snake venom, tumors: craniopharyngioma, germinoma, lymphoma, leukemia, meningioma, pituitary

Nephrogenic (Annals 2006;144:186)

congenital (ADH receptor V2 mutation, aquaporin-2 mutation; Pediatric Clinics 2019;66:227)

drugs: lithium, amphotericin, demeclocycline, foscarnet, cidofovir, ifosfamide

metabolic: hypercalcemia, severe hypokalemia, protein malnutrition, congenital

tubulointerstitial: postobstruction, recovery phase of ATN, PKD, sickle cell, Sjögren’s, amyloid, pregnancy (placental vasopressinase)

DI usually presents as severe polyuria and mild hypernatremia