Bilirubin Test

What is the bilirubin test?

The bilirubin test is a blood test that measures a substance called bilirubin in the blood. Bilirubin is released into the blood when red blood cells break down. The liver uses bilirubin to make bile.

Normally there is only a small amount of bilirubin in the blood. High levels may be caused by problems in the liver or in the blood. When there is a lot of bilirubin, the skin and whites of the eyes get yellow. The yellow color of the skin and eyes is called jaundice.

Why is this test done?

This test may be done to:

• See how well your liver is working.
• Check for blockage of bile in the bile duct, gallbladder, or liver. Bile, which contains bilirubin, is normally released into the intestines through the bile duct. If the bile duct is blocked, or if there is a blockage in the gallbladder or liver, there is more bilirubin in the blood because it is not longer released into the intestines.
• Check for certain blood problems, such as some types of anemia. Blood problems may cause a high level of bilirubin because more red blood cells are breaking down than normal.

How do I prepare for this test?

• If you are having other liver tests as well, you may need to fast for at least a few hours before the test. This means you should not eat or drink anything for several hours before the test. Other liver tests that are usually done at the same time as the bilirubin test are not as accurate if you have eaten. Ask your healthcare provider how long you should fast. If your healthcare provider says to take your medicines before your blood tests, you may take them with a small amount of water on the morning of your test.
• You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your healthcare provider knows about any medicines, herbs, or supplements that you are taking. Don't stop any of your regular medicines without first consulting with your healthcare provider.
• Talk to your healthcare provider if you have any questions about preparing for the test.

How is the test done?

A small amount of blood is taken from your arm with a needle. The blood is collected in tubes and sent to a lab.

Having this test will take just a few minutes.

How will I get the test result?

Ask your healthcare provider when and how you will get the result of your test.

What does the test result mean?

The normal bilirubin range is 0.1 to 1.2 milligrams per deciliter (mg/dL). The normal range may vary slightly from lab to lab. Normal ranges are usually shown next to your results in the lab report.

Your level of bilirubin may be higher than normal because:

• You have Gilbert's syndrome, which causes slightly increased levels of bilirubin. Gilbert's syndrome is a harmless genetic condition that causes no symptoms other than mild jaundice.
• You are taking a medicine that raises the bilirubin level in your blood.
• You have an infection.
• You have a liver or biliary tract disease, such as hepatitis or gallstones.
• You have a blood problem, such as anemia.

A bilirubin level lower than normal is, in general, never cause for concern.

What if my test result is not normal?

Test results are only one part of a larger picture that takes into account your medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about your result and ask questions.

If your test result is not normal, ask your healthcare provider:

• if you need additional tests
• what you can do to work toward a normal value
• when you need to be tested again.