Blood and lab tests
What Is Bilirubin on a Blood Test?
Bilirubin · say it: bil-ee-ROO-binAlso written: total bilirubin, TBIL, direct bilirubin, indirect bilirubin
Short answer
Bilirubin is a yellow substance made when old red blood cells break down; the liver processes it so it can leave the body.
What it means
Red blood cells wear out after a few months and are broken down. One leftover product is bilirubin, a yellow-orange pigment. The liver changes it into a form that can be passed out in bile and stool.
If too much bilirubin is made, or the liver or bile ducts cannot handle it properly, the level in the blood rises. High levels can cause jaundice, a yellowing of the skin and the whites of the eyes.
Reports may show total bilirubin and split it into direct (conjugated, processed by the liver) and indirect (unconjugated, not yet processed). The split helps doctors think about where a problem might be.
Where you may see it
- Liver function tests
- Newborn jaundice checks
- Comprehensive metabolic panels
📄 How it looks on a report
Bilirubin, total 26 umol/L H
🙅 What it does not mean
- A raised bilirubin does not automatically mean liver disease. A common, harmless inherited condition called Gilbert syndrome can mildly raise it.
- It does not tell you the cause on its own; the pattern with other tests matters.
- Jaundice in newborns is common and is assessed differently from bilirubin in adults.
🗒️ Questions to ask your doctor
🧾 Reports where you will see “Bilirubin”
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💊 Medicines whose labels mention “Bilirubin”
Plain-English explanations of each medicine, from its official FDA label.
- Ceftriaxone
A broad-spectrum cephalosporin antibiotic, as described on the official FDA label
- Rifampin
an antibiotic of the rifamycin type
- Sulfamethoxazole and Trimethoprim
An antibacterial combination of two medicines: a sulfonamide antimicrobial and a dihydrofolate reductase inhibitor antibacterial.
🔗 Read more from trusted sources
- “Bilirubin” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “bilirubin”
- MedlinePlus lab test guides ↗
US National Library of Medicine
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General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.