BUN Test
Nitrogen waste from protein metabolism that your kidneys clear. A general kidney-function indicator.
What is BUN?
Nitrogen waste from protein metabolism that your kidneys clear. A general kidney-function indicator.
BUN Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 7.00 – 20.0 mg/dL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your BUN result may mean
Often reflects dehydration, high-protein diets, or reduced kidney function.
Can reflect low-protein intake, liver disease, or overhydration.
Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
Sources
Related Metabolic Health biomarkers
Markers commonly tested alongside BUN.
Frequently asked
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