BUN
Medical abbreviation · Laboratory Test
| Stands for | Blood urea nitrogen |
|---|---|
| Categories | Medical |
BUN stands for Blood urea nitrogen, a laboratory test abbreviation.
Measures the nitrogen in urea, the waste product the liver makes from protein breakdown and the kidneys excrete. A typical adult range is about 7 to 20 mg/dL; high values occur with dehydration, kidney dysfunction, gastrointestinal bleeding, high-protein intake and steroids, while low values suggest liver disease, malnutrition or overhydration.
Example: BUN 48 with creatinine 1.4 and dark stools; suspect an upper GI bleed.
Usage notes
Said as letters or as the word "bun". The BUN-to-creatinine ratio helps localize kidney problems: above about 20 to 1 favors a prerenal cause such as dehydration or bleeding, because urea is reabsorbed while creatinine is not. BUN is a weaker marker of kidney function than creatinine since so many non-kidney factors move it. Outside the US, urea itself is reported in mmol/L.
Related abbreviations
More laboratory test abbreviations
- ASO – Antistreptolysin O
- AST – Aspartate aminotransferase
- BCx – Blood cultures
- BE – Base excess
- BG – Blood glucose
- BMP – Basic metabolic panel
- C&S – Culture and sensitivity
- Ca – Calcium
- CAP – College of American Pathologists
- CBC – Complete blood count
- CBC w/ diff – Complete blood count with differential
- Chem 7 – Seven-test chemistry panel
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This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.