What is Bilirubin Test? Purpose, Levels, Procedure & Results

A bilirubin test measures the amount of bilirubin in your blood. Bilirubin is a yellow substance that forms when your red blood cells break down naturally. Your liver processes this bilirubin and helps remove it from your body through bile. When bilirubin levels get too high, it can signal problems with your liver, gallbladder, or red blood cells.

What is bilirubin?

Bilirubin is a natural waste product that your body creates every day. When your red blood cells reach the end of their life cycle, they break apart and release a substance called hemoglobin. Your body then converts this hemoglobin into bilirubin.

There are two main types of bilirubin in your blood. Unconjugated bilirubin (also called indirect bilirubin) travels from your bloodstream to your liver. Conjugated bilirubin (also called direct bilirubin) has been processed by your liver and is ready to leave your body through bile.

Your liver acts like a processing plant for bilirubin. It takes the unconjugated form and transforms it into the conjugated form, which can then be eliminated through your intestines. This process happens smoothly when everything is working well.

Why is bilirubin test done?

Doctors order bilirubin tests to check how well your liver is working and to investigate possible causes of jaundice. Jaundice is the yellowing of your skin and eyes that happens when bilirubin builds up in your blood.

Your doctor might recommend this test if you have symptoms like yellow skin or eyes, dark urine, or pale stools. These signs can indicate that bilirubin isn't being processed or eliminated properly. The test also helps monitor liver diseases and track how well treatments are working.

Sometimes, bilirubin testing is part of routine blood work during physical exams. It can catch liver problems early, before you notice any symptoms. Your doctor might also use it to investigate unexplained fatigue, abdominal pain, or nausea.

What is the procedure for bilirubin test?

The bilirubin test is a simple blood draw that takes just a few minutes. A healthcare worker will clean a small area on your arm and insert a thin needle into a vein, usually in your elbow area.

You'll feel a quick pinch when the needle goes in, but most people find it quite tolerable. The blood sample gets collected in a small tube, and then the needle is removed. A small bandage goes over the spot where the needle was inserted.

The entire process typically takes less than five minutes. Your blood sample gets sent to a laboratory where technicians measure the different types of bilirubin. Results are usually available within a day or two.

How to prepare for your bilirubin test?

Most bilirubin tests don't require any special preparation. You can eat and drink normally before the test unless your doctor specifically tells you otherwise.

However, you should let your doctor know about any medications you're taking. Some medicines can affect bilirubin levels, including antibiotics, birth control pills, and certain pain relievers. Your doctor will decide if you need to temporarily stop any medications before the test.

If you're having other blood tests done at the same time, your doctor might ask you to fast for 8-12 hours beforehand. Always follow the specific instructions your healthcare provider gives you.

How to read your bilirubin test results?

Normal bilirubin levels are typically very low in healthy adults. Total bilirubin levels usually range from 0.2 to 1.2 milligrams per deciliter (mg/dL) of blood. Direct bilirubin should be less than 0.3 mg/dL.

When your results come back, you'll see numbers for total bilirubin, direct bilirubin, and indirect bilirubin. Indirect bilirubin is calculated by subtracting direct bilirubin from total bilirubin. Your doctor will explain what these numbers mean for your specific situation.

Keep in mind that different laboratories might use slightly different ranges for normal values. Your doctor will interpret your results based on your symptoms, medical history, and other test results. What matters most is the overall pattern and how your levels compare to what's normal for you.

What causes high bilirubin levels?

High bilirubin levels can happen for several different reasons, and your doctor will work with you to find the specific cause. The location of the problem helps determine what might be going wrong.

Here are the main categories of conditions that can raise bilirubin levels:

• Liver problems: Hepatitis, cirrhosis, fatty liver disease, liver cancer, or inherited liver disorders
• Gallbladder and bile duct issues: Gallstones, bile duct blockages, or inflammation of the bile ducts
• Blood-related conditions: Hemolytic anemia, sickle cell disease, or malaria
• Inherited conditions: Gilbert's syndrome, Crigler-Najjar syndrome, or Dubin-Johnson syndrome
• Medication effects: Certain antibiotics, steroids, or chemotherapy drugs

Some causes are more serious than others, and many are very treatable. Your doctor will consider your symptoms and other test results to determine which possibility is most likely in your case.

What are the symptoms of high bilirubin?

The most obvious sign of high bilirubin is jaundice, which causes your skin and the whites of your eyes to turn yellow. This happens because excess bilirubin builds up in your tissues.

You might also notice other symptoms that can accompany high bilirubin levels:

• Dark yellow or brown urine
• Pale or clay-colored stools
• Itchy skin all over your body
• Fatigue or feeling unusually tired
• Nausea or loss of appetite
• Abdominal pain, especially in the upper right area

These symptoms can vary depending on what's causing your high bilirubin. Some people might have very mild symptoms, while others feel quite unwell. The severity often depends on how high your bilirubin levels are and how quickly they rose.

What are the complications of high bilirubin?

Most cases of high bilirubin are manageable when caught early and treated properly. However, severely high levels can sometimes lead to complications, especially in newborns.

In babies, very high bilirubin levels can potentially cause a rare but serious condition called kernicterus. This happens when bilirubin builds up in the brain and can cause hearing loss, vision problems, or developmental delays. This is why doctors monitor bilirubin levels closely in newborns.

In adults, complications are more likely to come from the underlying condition causing high bilirubin rather than from the bilirubin itself. For example, if liver disease is causing high bilirubin, the liver problems pose the greater health risk.

Chronic high bilirubin levels can sometimes lead to the formation of gallstones. These are hard deposits that can block bile ducts and cause pain or other problems. Regular monitoring helps catch these issues early.

How to lower high bilirubin levels?

Treating high bilirubin focuses on addressing the underlying cause rather than just lowering the number. Your doctor will create a treatment plan based on what's causing your elevated levels.

For liver-related causes, treatment might include medications to protect liver function, lifestyle changes like avoiding alcohol, or treatments for specific liver conditions. If gallstones are blocking bile ducts, you might need procedures to remove them.

Here are some general approaches that might help support healthy bilirubin levels:

• Staying well-hydrated by drinking plenty of water
• Eating a liver-friendly diet with plenty of fruits and vegetables
• Avoiding alcohol and limiting processed foods
• Getting regular exercise as tolerated
• Taking prescribed medications exactly as directed
• Following up with your doctor regularly for monitoring

Some people with mild elevations, particularly those with Gilbert's syndrome, might not need any specific treatment. Your doctor will help you understand what approach is best for your situation.

What about low bilirubin levels?

Low bilirubin levels are generally not a cause for concern. In fact, having bilirubin levels on the lower end of normal is usually considered a good thing, as it suggests your liver is processing bilirubin efficiently.

Very rarely, extremely low bilirubin levels might indicate certain conditions like coronary artery disease or be related to medications that affect bilirubin metabolism. However, doctors typically don't worry about low bilirubin unless it's part of a pattern with other abnormal test results.

If your bilirubin levels are low, your doctor will likely focus on any other abnormal findings in your blood work rather than the low bilirubin itself. This is quite different from high bilirubin, which usually needs investigation and treatment.

When should I see a doctor about bilirubin levels?

You should contact your doctor if you notice yellowing of your skin or eyes, as this could indicate high bilirubin levels. This is especially important if the yellowing appears suddenly or is accompanied by other symptoms.

Other signs that warrant medical attention include dark urine that looks like tea or cola, very pale stools, severe itching all over your body, or persistent fatigue combined with nausea. These symptoms together often point to problems with bilirubin processing.

If you've been diagnosed with a condition that affects bilirubin levels, follow your doctor's recommendations for regular monitoring. This might include periodic blood tests to track your levels and ensure your treatment is working effectively.

Don't hesitate to reach out if you have concerns about your symptoms or test results. Your healthcare team is there to help you understand what's happening and develop the best plan for your health.