The ratio is derived by dividing the blood urea nitrogen (BUN) value by the creatinine value. For instance, a BUN of 20 mg/dL and a creatinine of 1 mg/dL yields a ratio of 20. Both measurements are routinely obtained through a standard blood test.
Comparing these two values provides valuable insights into kidney function and overall hydration status. Historically, this calculation has served as a crucial diagnostic tool, helping healthcare professionals differentiate between various causes of kidney dysfunction, such as dehydration, reduced blood flow to the kidneys, or intrinsic kidney disease. A normal ratio typically falls within a specific range, with deviations suggesting potential underlying issues.