What does the BUN test evaluate?

The BUN test, which stands for Blood Urea Nitrogen test, primarily evaluates kidney function. Urea nitrogen is a waste product formed in the liver when the body breaks down protein, and it is typically eliminated from the body by the kidneys through urine. Therefore, measuring the level of BUN in the blood helps to assess how well the kidneys are filtering out waste.

Elevated levels of BUN may indicate that the kidneys are not functioning properly, possibly due to conditions such as kidney disease, dehydration, or urinary obstruction. Conversely, lower than normal levels may indicate liver issues or overhydration. This test is crucial in diagnosing and monitoring renal health and function. Understanding the role of BUN in assessing kidney performance underscores its importance in phlebotomy and clinical practices.