Indirect Bilirubin
Does this test have other names?
Unconjugated bilirubin
What is this test?
This test measures the amount of bilirubin in your blood. Your body makes bilirubin
when it breaks down hemoglobin. Hemoglobin is a protein in red blood cells. The breakdown
of hemoglobin is called hemolysis.
Your liver removes bilirubin from your body. So measuring bilirubin is one way to
check how well your liver is working.
Why do I need this test?
You may need this test if the results of a total bilirubin blood test are abnormal.
Your total bilirubin may be tested if your healthcare provider suspects you have certain
health conditions. These include transfusion reaction, Gilbert syndrome, Dubin-Johnson
syndrome, Rotor syndrome, or Crigler-Najjar syndrome. It may also be done as part
of routine blood testing to screen for liver problems or damage such as cirrhosis.
Or it may be done to screen for a blood disease such as hemolytic anemia or pernicious
anemia. You may also have bilirubin testing to track a disease you have or are being
treated for.
What other tests might I have along with this test?
Your healthcare provider may order many other tests along with direct, indirect, and
total bilirubin that assess your liver health. These tests are called liver function
tests and may include:
What do my test results mean?
Test results may vary depending on your age, gender, health history, the method used
for the test, and other things. Your test results may not mean you have a problem.
Ask your healthcare provider what your test results mean for you.
Indirect and direct bilirubin make up your total bilirubin. When total bilirubin is
abnormal, it is important to measure direct and indirect bilirubin levels. Bilirubin
is measured in milligrams per deciliter (mg/dL). An example of normal values for adults
is:
Indirect bilirubin is the difference between total and direct bilirubin.
Common causes of higher indirect bilirubin include:
-
Hemolytic anemia. This means your body is getting rid of too many red blood cells.
-
Bleeding into the skin caused by injury
-
Bleeding in the lung caused by a blood clot
-
A gene problem that causes slightly higher indirect bilirubin levels without other
signs or symptoms of disease
How is this test done?
The test is done with a blood sample. A needle is used to draw blood from a vein in
your arm or hand.
Does this test pose any risks?
Having a blood test with a needle carries some risks. These include bleeding, infection,
bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may
feel a slight sting or pain. Afterward, the site may be sore.
What might affect my test results?
Different things may affect bilirubin levels. Vigorous exercise can raise bilirubin
levels. So can the HIV medicine atazanavir.
Caffeine can lower total bilirubin. So can certain medicines. These include:
Men have slightly higher levels of bilirubin than women. African Americans also have
slightly higher levels of bilirubin than people of other ethnic backgrounds.
How do I get ready for this test?
You may need to fast several hours before this test. Ask your healthcare provider
how you should prepare for the test. Instructions can vary.
Several types of medicine may change the bilirubin level in your blood. Be sure your
healthcare provider knows about all medicines, herbs, vitamins, and supplements you
are taking. This includes medicines that don't need a prescription and any illicit
drugs you may use.