Bilirubin Test

What type of results will I get and what do the results mean?

The test results will show measurement values for the bilirubin in your bloodstream. There are actually two different types of bilirubin in your bloodstream: the bilirubin that goes to your liver for processing, and the bilirubin that comes out of your liver. Your test will show these values separately, as well as your total bilirubin. It’ll usually show them as milligrams of bilirubin per deciliter of blood, or mg/dL.

Direct vs. indirect bilirubin (or conjugated vs. unconjugated)

The bilirubin that goes to your liver for processing is “unconjugated,” which means it’s not water-soluble (dissolvable in water). It’s bound to a protein in your blood called albumin that helps carry it to your liver. When your liver processes the bilirubin, it unbinds it from the albumin and binds it to a sugar molecule, making it water-soluble. This allows it to mix with bile and pass through your intestines.

“Conjugated” bilirubin is the bilirubin your liver processed. Sometimes it’s called “direct” bilirubin on your test results. That’s because this type can be measured directly. Unconjugated bilirubin can’t be measured directly. It’s measured by subtracting the value of conjugated bilirubin from the value of total bilirubin in your blood. Unconjugated bilirubin may be called “indirect” bilirubin on your test results.

At what level is bilirubin a concern?

Different labs may have slightly different ranges for what they consider normal bilirubin levels. On average, total bilirubin levels between 0.2 and 1.3 mg/dL are considered normal for children and adults. If your levels are higher, your healthcare provider may want to investigate further to look for the cause. It may suggest a problem that needs attention. But high bilirubin itself won’t usually need treatment.

It’s a little different for newborns. Normal levels for newborns can range anywhere between 1.0 and 12.0 mg/dL. Most of the time, hyperbilirubinemia in newborns is predictable and self-limited. But healthcare providers continue to monitor these cases to make sure bilirubin levels don’t rise too far or too fast. This could indicate a more serious condition, and it could also be toxic to the newborn.

What level of bilirubin is dangerous?

Healthcare providers recommend treatment for newborns when bilirubin levels rise above 15 mg/dL in the first 48 hours or 20 mg/dL after 72 hours. At these levels, unconjugated bilirubin exceeds the amount of available albumin to bind it. The unconjugated bilirubin can cross the blood-brain barrier in newborns and harm their developing brains. It can cause varying degrees of brain damage, called kernicterus.

This risk isn’t the same for children and adults. Adult brains aren’t as vulnerable, and adults aren’t as likely to have such high levels of unconjugated bilirubin. Newborns produce bilirubin faster than adults do, and they conjugate it much slower. There are many more causes of conjugated hyperbilirubinemia in adults. For adults, hyperbilirubinemia might signal a dangerous condition, but the bilirubin itself isn’t dangerous.

What does it mean when your bilirubin is high?

You might have higher levels of unconjugated (indirect) bilirubin if your body is breaking down red blood cells faster than your liver can keep up with. This might indicate:

• Hemolytic disease.
• Sickle cell disease.
• Adverse reaction to a blood transfusion.

Common causes of unconjugated bilirubinemia in newborns include:

• Premature birth.
• Mismatched blood type between the baby and mother.
• Reactions to substances in breast milk.

You might have higher levels of conjugated bilirubin (direct) if your body is having trouble clearing it. This might indicate a biliary disease or gallstone disease, such as:

• Gallstones.
• Cholecystitis.
• Cholangitis.

Conditions that affect your liver’s ability to process bilirubin will cause high levels of both types to build up in your blood.

You might have a higher total bilirubin count if something is temporarily stressing your liver, such as a new medicine or a high dose of alcohol. It could also indicate an acute or chronic liver disease. Some causes include:

• Infections such as viral hepatitis and mononucleosis.
• Genetic conditions that affect bilirubin metabolism, such as Gilbert’s syndrome, Wilson disease and Crigler-Najjar syndrome.
• Toxic hepatitis (alcohol-induced or drug-induced).
• Cirrhosis and chronic liver failure.

If my test results are abnormal, what happens next?

A healthcare provider will review your symptoms and health history to try and identify likely causes. Different causes will have different treatment options. They may suggest further blood tests or imaging tests to help diagnose your condition. They may also test your bilirubin levels again to make sure they aren’t rising. If bilirubin rises too high in your newborn, they’ll recommend treatment to reduce it.

What is the treatment for high bilirubin in newborns?

Phototherapy is the standard treatment to reduce bilirubin levels in newborns. A healthcare provider places your infant under a lamp that emits fluorescent white or blue-spectrum light. The light helps break down the bilirubin into a water-soluble form so that the body can excrete it without conjugating it in the liver. This prevents unconjugated bilirubin from depositing in your newborn’s brain tissue.

How do you lower your own bilirubin levels?

Your bilirubin levels will go down if you can effectively treat or manage the condition that’s causing them to rise. This depends on the condition. Your healthcare provider will discuss your options for either curing or reducing its effects. In general, you can reduce overall stress on your liver by eliminating alcohol and drugs — including over-the-counter (OTC) medications, if possible — and maintaining a healthy diet.