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A blood urea nitrogen (BUN) or urea test measures the amount of nitrogen in your blood that comes from the waste product urea. Urea is made in the liver and passed out of your body in the urine. If your kidneys are not able to remove urea from the blood normally, your urea level rises. Dehydration can also make your urea level higher.
A urea test may be done with a blood creatinine test. The level of creatinine in your blood also tells how well your kidneys are working. A high creatinine level may mean your kidneys are not working properly. Urea and creatinine tests can be used together to find the urea-to-creatinine ratio.
A urea test is done to:
Do not eat a lot of meat or other protein in the 24 hours before having a urea test.
A health professional uses a needle to take a blood sample, usually from the arm.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.
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Adaptation Date: 2/28/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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