Kidney Function
Normal range 7–20 mg/dL (2.5–7.1 mmol/L (urea) SI). Specimen: Serum or plasma.
Also known as: urea nitrogen, urea.
| Specimen | Serum or plasma |
|---|---|
| Conventional range | 7–20 mg/dL |
| SI range | 2.5–7.1 mmol/L (urea) |
| Conversion factor | ×0.357 (conventional → SI) |
| Critical value | > 100 mg/dL suggests serious renal impairment |
| Panel | Kidney Function |
Convert any Blood Urea Nitrogen (BUN) result between units on the unit converter.
The standard teaching reference range for Blood Urea Nitrogen (BUN) is 7–20 mg/dL in conventional units, or 2.5–7.1 mmol/L (urea) in SI units. This value is measured in serum or plasma.
A commonly taught critical (panic) value is > 100 mg/dL suggests serious renal impairment. Critical results are reported to the provider immediately under your facility's policy.
Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population — always use the range printed on the actual result.
Above the range
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