What is a BUN (blood urea nitrogen) test?A BUN, or blood urea nitrogen test, can provide important information about your kidney function. The main job of your kidneys is to remove waste and extra fluid from your body. If you have kidney disease, this waste material can build up in your blood and may lead to serious health problems, including high blood pressure, anemia, and heart disease.The test measures the amount of urea nitrogen in your blood. Urea nitrogen is one of the waste products removed from your blood by your kidneys. Higher than normal BUN levels may be a sign that your kidneys aren't working efficiently.People with early kidney disease may not have any symptoms. A BUN test can help uncover kidney problems at an early stage when treatment can be more effective.Other names for a BUN test: Urea nitrogen test, serum BUN
