The blood urea nitrogen (BUN) to creatinine ratio is a clinical laboratory value derived from two separate blood tests: BUN, which measures the amount of urea nitrogen in the blood, and creatinine, a waste product from muscle metabolism. The resulting ratio assists in evaluating kidney function and can provide clues regarding the underlying cause of kidney problems. For instance, a disproportionately elevated ratio compared to the individual BUN and creatinine levels can point towards certain clinical scenarios.
Evaluating this ratio is beneficial as it aids in the differential diagnosis of kidney-related issues. Clinicians can use the ratio, in conjunction with other clinical information, to distinguish between pre-renal, intrinsic renal, and post-renal causes of kidney dysfunction. Historically, the ratio has been employed as a readily available marker in routine blood tests to prompt further investigation of potential renal or systemic disorders that impact kidney function.
