Urine specific gravity < 1.010
Measure serum and urine sodium while patient is water-deprived
Lack of response to water deprivation is<unk> agnostic
Serum Osm >295 mOsm/L
Record response to 5 units subcutaneous vasopressin
Response to vasopressin is<unk> agnostic of central<unk>  (response is indicated by urine osm >800 mOsm/L)
No response is<unk> agnostic of nephrogenic<unk> 
In adults, onset of central<unk>  usually abrupt whereas onset gradual in nephrogenic<unk> 
Lack of response to water deprivation is<unk> agnostic
Serum Osm >295 mOsm/L
Response to vasopressin is<unk> agnostic of central<unk>  (response is indicated by urine osm >800 mOsm/L)
No response is<unk> agnostic of nephrogenic<unk>
Diabetes insipidus
Water loss:
Dysuria
Decreased Intake
Polyuria
Water loss > Na loss
Acute urinary retention
Vomiting