BUN

CPT Code

84520

Specimen Type

Blood

Container Type

Serum Separator Tube (SST)/Yellow

Stability

Room Temperature, 7 days; 2-8° C, 7 days; -20° C, 1 year

Handling Instructions

Allow to clot for 30 mins, centrifuge within 2 hours

Clinical Notes

As the test name indicates, a BUN test measures urea nitrogen in the blood. Urea, often called urea nitrogen, is a waste product that is produced as a result of the breakdown of proteins in the body. The kidneys work to filter urea out of the blood so that it can be cleared out of the body in the urine. As this process unfolds, it’s normal for some urea to be in the blood. But when BUN levels are too high, it can be an indication that the kidneys are not functioning properly.