WHAT IS WATER LOADING TEST?
The water loading test involves administering a large quantity of water and then comparing the osmolality of timed urine and serum collections. In a normal client, increased fluid intake increases urine output and decreases urine osmolality. In clients with SIADHS, however, excess secretion of the antidiuretic hormone causes a lower-than-normal urine output in response to the water loading and a urine osmolality that does not decrease below serum osmolality.