Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
It's part of basic and comprehensive metabolic panels.
Why it's done
- Kidney function checks
- Dehydration
- Bleeding in the stomach or upper intestine (can raise BUN)
Getting ready and what happens
- No special preparation is usually needed.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
What the results mean
| Result | Typical range for adults |
|---|---|
| BUN | About 7 to 20 mg/dL |
Normal ranges vary from lab to lab and can differ by age, sex, and pregnancy. Your report lists your lab's own range next to each result. A result a little outside the range is often not a problem.
High
Common with dehydration, high-protein diets, kidney disease, heart failure, steroids, and upper gut bleeding.
Low
Usually not a concern; can occur with liver disease or low protein intake.
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related tests
Sources
Last updated 2026-11-13.