Blood Urea Nitrogen (BUN) Test
Blood Urea Nitrogen (BUN) Test measures the amount of urea nitrogen found in your blood. Urea nitrogen is a waste product made when your liver breaks down protein. It's carried in your blood, filtered out by your kidneys, and removed from your body in your urine. If your liver isn't healthy, it may not break down proteins the way it should. And if your kidneys aren't healthy, they may not properly filter urea. Either of these problems can lead to larger amounts of urea nitrogen in your body.
Preparation: No special preparation is needed for this test. No fasting is needed