A blood urea nitrogen (BUN) test measures the amount of nitrogen in your blood that comes from the waste product urea. Urea is formed when protein is broken down in your body. It is made in the liver and removed from your body in urine.
A BUN test is done to tell how well your kidneys are working. If your kidneys are not able to remove urea from the blood normally, your BUN level increases. Heart failure, dehydration, certain medicines, intestinal bleeding, or a diet high in protein also can increase your BUN level. Liver disease or damage can decrease your BUN level, because urea is made in the liver. A decreased BUN level can occur normally in the second or third trimester of pregnancy.
© 1995-2007, Healthwise, Incorporated, P.O. Box 1989, Boise, ID 83701. ALL RIGHTS RESERVED.
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information. For more information, click here. Privacy Policy. How this information was developed.
