A BUN of 6
| Where it fallscommonly reported adult reference ranges | Below the reference range |
|---|---|
| BUN | 6mg/dL |
| Usual reference range | 7 – 20mg/dL |
| Same result as ureaoutside the US the same substance is reported as urea, a different number for the same thing | 2.1mmol/L |
| Below the reference rangethis reading | under 7mg/dL |
| Normal | 7 – 20mg/dL |
| Above the reference range | 21 – 39mg/dL |
| Markedly raised | 40 and abovemg/dL |
Notes
- One reading is not a diagnosis. BUN moves with hydration, protein intake, bleeding in the gut, steroids and heart function, as well as the kidneys. A clinician reads it against your history and usually against a repeat, not on its own.
- Reference ranges differ between laboratories. The bands above follow commonly reported adult reference ranges. Your own report prints the range its analyser was calibrated against, and that printed range is the one to compare against — a difference of a few units between labs is normal and does not mean either is wrong.
- BUN and urea are the same measurement reported two ways. The United States reports blood urea nitrogen — just the nitrogen part — while most other countries report the whole urea molecule in mmol/L. Comparing a US result to a UK one without converting produces an apparent difference of nearly threefold, and it is a routine source of alarm among people who move between health systems.
- The BUN-to-creatinine ratio separates two very different pictures. A ratio above about 20:1 with a normal creatinine usually means dehydration or bleeding into the gut rather than kidney disease; a ratio nearer 10:1 with both raised points at the kidney itself. That is why the two are almost always reported together.
What bun of 6 mg/dL means
A reading of 6 mg/dL falls in Below the reference range by commonly reported adult reference ranges.
The usual reference range is 7 – 20 mg/dL.
Reading it next to the rest of the picture
A single figure is a snapshot. What somebody experienced does with it is set by what sits around it — the other figures on the same report, the history behind them, and what the previous result was. Two people can hand over the same number and leave with different advice, and neither has been given the wrong answer.
That is also why the bands on this page are drawn from a named source rather than a rounded rule of thumb. A threshold is a decision point somebody argued for in print, not a law of nature, and knowing which document a line comes from is what lets you tell a meaningful result from a borderline one.
Nearby sizes
Read more
- CBC Normal Ranges — What Each Line on the Result MeansA value marked high or low on a CBC is common and is often not significant on its own. The pattern across lines is what a clinician reads.
- eGFR Normal Range: Above 90, and the Stages Below IteGFR is an estimate built from creatinine, age and sex — and the estimate is better than the raw creatinine it comes from, for a reason worth understanding.
- TSH Normal Range: 0.4–4.0 mIU/L, and the Number Moves BackwardsTSH runs opposite to the gland it measures. High TSH means the thyroid is underactive, and that inversion catches almost everyone reading their own result.
- Cholesterol Numbers: What Total, LDL, HDL and Triglycerides MeanA lipid panel reports four numbers and the one printed largest — total cholesterol — is the least useful of them.