ADH: 1–5 pg/mL; SI units: <1.5 ng/L
ADH suppression test: 80% of waterload excreted in 5 hr; Urine
osmolality ≥100 mmol/kg; Urine to serum osmolality ratio >100;
Urine specific gravity <1.003.
. Red-top tube, plastic.
■ ADH controls the amount of water resorbed by the kidney.
■ Inadequate ADH secretion results in diabetes insipidus (DI).
■ Excess secretion of ADH related to various cancers (lung,
pancreas, urinary tract, blood) results in syndrome of
inappropriate ADH (SIADH).
