Reference ranges
BUN reference range
Reference ranges describe the interval a laboratory prints next to your result. They are not a diagnosis of what is “normal” for you personally — your clinician interprets results in context.
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What BUN measures
The liver produces urea as protein is broken down; the kidneys clear it into urine. Labs report the nitrogen portion of urea circulating in blood.
Why ranges differ
Laboratories set their own reference intervals using their methods, equipment, and population data. That is why the range on your Quest report may differ from a LabCorp report — always use the interval printed on your source document.
Common units
BUN is often reported in mg/dL. Confirm units on your original report before comparing values across time.