<unk>  is a measure of urine concentration, in which large values indicate concentrated urine and small values indicate diluted urine. Consumption of water (including water contained in food) affects the osmolality of<unk>  is measured by osmometer, which evaluates the freezing point depression of a solution and supplies results as milliosmoles per kilogram of water while specific gravity is measured by colorimetric strips, refractometer, hydrometer and pyknometer. In healthy humans with restricted fluid intake,<unk>  should be greater than 800 mOsm/kg, while a 24-hour<unk>  should average between 500 and 800 mOsm/kg.<unk>  in humans can range from approximately 50 to 1200 mOsm/kg, depending on whether the person has recently drunk a large quantity of water (the lower number) or has gone without water for a long time (the higher number). Plasma osmolality with typical fluid intake often averages approximately 290 mOsm/kg H2O in humans.
Urine osmolality
Urine sodium
Plasma osmolality
Urine flow rate
Urine anion gap
Urine urea nitrogen
BUN-to-creatinine ratio
Microalbuminuria