Urea
Blood Urea
- Sample
- Blood
- Usual units
- mg/dL
Also known as Blood Urea · Serum Urea · S. Urea
What this test measures
Urea is a nitrogen-containing waste substance made by the liver during protein processing and carried in blood to the kidneys. A blood test measures its concentration, usually in milligrams per deciliter (mg/dL).
Reading your report
There isn’t one standard range for this test — each lab prints its own. Use the range shown next to your result.
Urea unit converter
Convert Urea units
Labs print this test in mg/dL or mmol/L depending on where the sample was run.
Related guides
- Guide
Why the same blood test has different "normal" ranges at different labs
Reference intervals are built from each lab's own population and equipment, which is why two labs can print different ranges for the same sample.
- Guide
Reference interval, cutoff, and the "optimal" numbers online: three different things
The range beside your result, the target a website quotes, and the threshold that defines a condition are built in different ways and answer different questions.
- Guide
Why the same lab printed a different reference range for you this year
Ranges are not fixed constants. The lab can change method, revise its reference group, or apply a range that depends on your age — none of which is an error.
- Guide
Creatinine, eGFR and urea: one measured, the others worked out from it
A kidney panel prints a waste product, an estimate derived from it, and a second waste product measured separately. Which is which, and why eGFR can move when creatinine doesn't.