A BUN test may be done with a blood creatinine test. Blood urea nitrogen (BUN) and creatinine tests can be used together to find the BUN-to-creatinine ratio (BUN:creatinine). To learn more, see the topic Creatinine and Creatinine Clearance.
BUN levels may be measured regularly in people who have kidney dialysis. BUN levels are used to see how well dialysis is working.