Bilirubin Blood Test Test
A bilirubin blood test measures the level of bilirubin in your blood. Bilirubin is a yellowish substance made when your body breaks down old red blood cells. High levels can cause jaundice (yellow skin or eyes) and may signal liver problems.
What this test measures
This test measures the amount of bilirubin in your blood. Bilirubin is a waste product from the breakdown of red blood cells, normally removed by the liver. If the liver is damaged or bile ducts are blocked, bilirubin can build up in the blood.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
High bilirubin levels (hyperbilirubinemia) may mean your liver isn't working right. Possible causes include hemolytic anemia, liver disease, or a blockage in your bile ducts. Certain medicines, foods, or strenuous exercise can also raise levels.
Lower-than-normal results
Low bilirubin levels are not usually a cause for concern. They may be due to medicines such as antibiotics, birth control pills, sleeping pills, or seizure medicines.
Frequently asked questions
What is a bilirubin blood test?
It measures the level of bilirubin in your blood. Bilirubin is a yellowish waste product made when old red blood cells break down.
Why might I need this test?
To check your liver health, find the cause of jaundice, or see how well a treatment is working. It is also commonly used to diagnose newborn jaundice.
What does a high bilirubin level mean?
High levels may mean your liver isn't working properly. Possible causes include hemolytic anemia, liver disease, or a blocked bile duct. Some medicines, foods, or exercise can also raise levels.
What does a low bilirubin level mean?
Low levels are not usually a concern. They may be caused by certain medicines like antibiotics, birth control pills, sleeping pills, or seizure medicines.
What is jaundice?
Jaundice is a condition that causes your skin and eyes to turn yellow. It happens when too much bilirubin builds up in your blood.
Related lab tests
Sources
- MedlinePlus: Bilirubin Blood Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.