<Tr> <Th> LOINC </Th> <Td> 6299 - 2, 59570 - 2, 12961 - 9, 12963 - 5, 12962 - 7 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Blood urea nitrogen (BUN) is a medical test that measures the amount of urea nitrogen found in blood . The liver produces urea in the urea cycle as a waste product of the digestion of protein . Normal human adult blood should contain between 6 and 20 mg of urea nitrogen per 100 ml (6--20 mg / dL) of blood . Individual laboratories will have different reference ranges as the assay used will vary between laboratories . </P> <P> Blood urea nitrogen (BUN) is an indication of renal (kidney) health . The normal range is 1.8 - 7.1 mmol / L or 6--20 mg / dL . Blood urea nitrogen levels can also help identify damage to body systems and diseases of the digestive, circulatory and respiratory systems . </P>

What is the normal range for urea nitrogen