In medicine, the<unk>  is the ratio of two serum laboratory values, the blood urea nitrogen <unk>  (mg/dL) and serum<unk>  (Cr) (mg/dL). Outside the United States, particularly in Canada and Europe, the term urea is often used.<unk>  only reflects the nitrogen content of urea (MW 28) and urea measurement reflects the whole of the molecule (MW 60), urea is approximately twice (60/28 = 2.14) that of<unk> . In Canada and Europe the units are also different (mmol/L). The units of<unk>  are also different (μmol/L), and this value is termed the urea-to-creatinine ratio. The ratio may be used to determine the cause of acute kidney injury or dehydration. The principle behind this ratio is the fact that both urea <unk>  and<unk>  are freely filtered by the glomerulus; however, urea reabsorbed by the tubules can be regulated (increased or decreased) whereas<unk>  reabsorption remains the same (minimal reabsorption).
BUN-to-creatinine ratio
Microalbuminuria
Urine osmolality
Urine urea nitrogen
Renal clearance ratio
Urine protein/creatinine ratio
Urea reduction ratio
Blood urea nitrogen