A love affair with cigars is like most affairs of the heart. We swoon over the beauty and elegance, but we never really know what makes us love--and we don't want to. To overanalyze a cigar, or a mate, is to destroy the mystery.
A blood urea nitrogen (BUN) test measures the amount of nitrogen in your blood that comes from the waste product urea. Urea is made when protein is broken down in your body. Urea is made in the liver and passed out of your body in the urine. A BUN test is done to see how well your kidneys are working.
BUN (Blood Urea Nitrogen) Test. The blood urea nitrogen (BUN) test is done to measure the amount of nitrogen in your blood. The nitrogen is present in a chemical called urea. Urea is a waste product your body makes when you digest food. Urea is carried by the blood to the kidneys. The kidneys filter the urea out of the blood and into the urine.