BLOOD UREA NITROGEN
A blood urea nitrogen (BUN) test measures the amount of urea nitrogen in your blood, which can help diagnose or monitor kidney disease. Urea nitrogen is a waste product that your body produces when it breaks down protein, and healthy kidneys filter it out of your blood. A higher than normal BUN level may indicate that your kidneys aren't working well.
Normal range
Adults
7–20 milligrams per deciliter (mg/dL)
The normal range can vary depending on age and other health conditions.
When to get a BUN test
Reason
Kidney problems
You have or are at risk for a kidney problem
Kidney disease symptoms
You have symptoms of later stage kidney disease, such as needing to urinate more often or less often than usual, or itching
What to consider
Details
Medications
Some prescription drugs, over-the-counter medications, and/or dietary supplements can affect a BUN test.
Preparation
You may need to modify your medication schedule before the test.
Other tests
If BUN is being tested with other measurements, such as in a BMP or CMP, you may need to fast for eight to 12 hours before the blood draw.
To reduce your BUN levels, you can limit high-protein foods such as meats and dairy products. You can also try a diet low in protein
