Table Water Deprivation Test Results Parameter Normal Complete Arginine Vasopressin Deficiency Partial Arginine Vasopressin Deficiency Complete Arginine Vasopressin Resistance Partial Arginine Vasopressin Resistance Primary Polydipsia Uosm after dehydration (step 1) Very high (> 700 - 800 mOsm / kg [> 700 - 800 mmol / kg]) Very low (less than plasma osmolality) Low (≥ 300 mOsm / kg [≥ 300 mmol / kg]) Very low (less than plasma osmolality) Very low (less than plasma osmolality) High (500 - 600 mOsm / kg [500 - 600 mmol / kg]) Uosm increase after vasopressin (step 2) Minimal (< 5%) 50 to > 100% 15 - 50% < 50 mOsm / kg (<50> Up to 45% No change Uosm = urine osmolality.