Direct Bilirubin
Bilirubin Direct
- Sample
- Blood
- Usual units
- mg/dL
Also known as Bilirubin Direct · Bilirubin (Direct) · D. Bilirubin · Conjugated Bilirubin
What this test measures
Direct bilirubin is bilirubin that has been processed into a water-soluble form by the liver. 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.
Direct Bilirubin unit converter
Convert Direct Bilirubin units
Labs print this test in mg/dL or µmol/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
Total, direct and indirect bilirubin — and why the third is subtraction
Two of these three rows are measured and one is the difference between them. What bilirubin is, and why the split is reported at all.