Bilirubin Blood Test

The bilirubin blood test is a medical laboratory test used to measure the levels of bilirubin in the blood. Bilirubin is a yellow pigment that is produced during the breakdown of hemoglobin, which is the protein in red blood cells that carries oxygen.

Purpose

The purpose of the bilirubin blood test is to:

• Diagnose and monitor liver disease, such as hepatitis or cirrhosis
• Diagnose and monitor hemolytic anemia, a condition where red blood cells are broken down faster than they can be made
• Check for blockages in the bile ducts, which can cause jaundice (a yellowing of the skin and eyes)
• Monitor the effectiveness of treatment for liver or hemolytic disorders

Types of Bilirubin Tests

There are two types of bilirubin tests:

• Total bilirubin test: measures the total amount of bilirubin in the blood, including both conjugated and unconjugated bilirubin
• Direct bilirubin test: measures the level of conjugated (direct) bilirubin in the blood
• Indirect bilirubin test: measures the level of unconjugated (indirect) bilirubin in the blood

How the Test is Performed

The bilirubin blood test is performed by:

• Taking a blood sample from a vein, usually in the arm
• Sending the blood sample to a laboratory for analysis
• Measuring the levels of bilirubin in the blood using a spectrophotometer or other specialized equipment

Normal Results

The normal results for bilirubin tests vary depending on the laboratory and the individual being tested. Generally:

• Total bilirubin: 0.1-1.2 mg/dL (1.7-20.5 μmol/L)
• Direct bilirubin: 0.0-0.3 mg/dL (0-5.1 μmol/L)
• Indirect bilirubin: 0.1-1.0 mg/dL (1.7-17.1 μmol/L)

Abnormal Results

Abnormal results may indicate:

• Liver disease, such as hepatitis or cirrhosis
• Hemolytic anemia
• Blockages in the bile ducts
• Other medical conditions, such as cancer or infection

Risks and Limitations

The bilirubin blood test is a relatively safe and simple procedure. However:

• There may be some discomfort or bruising at the site where the blood sample was taken
• Some individuals may experience dizziness or lightheadedness after the test
• The test may not detect all cases of liver disease or hemolytic anemia, and additional testing may be necessary for diagnosis

Frequently Asked Questions (FAQs)

What is a bilirubin blood test?
Measures levels of bilirubin in the blood, which can indicate liver function and health.

Why is a bilirubin blood test ordered?
To diagnose and monitor conditions such as jaundice, liver disease, and hemolytic anemia.

What does high bilirubin level indicate?
May indicate liver dysfunction, bile duct obstruction, or excessive red blood cell breakdown.

How is the test performed?
A blood sample is drawn from a vein, typically in the arm, using a needle and syringe.

Is fasting required before the test?
Typically not required, but may be recommended in some cases to ensure accurate results.

What are normal bilirubin levels?
Vary by laboratory, but generally around 0.1-1.2 mg/dL for adults and 0.2-1.0 mg/dL for newborns.

Can medications affect bilirubin test results?
Yes, certain medications may increase or decrease bilirubin levels, such as barbiturates and rifampin.

Are there any risks associated with the test?
Minimal risks, including bruising, bleeding, or infection at the needle site.

How long does it usually take to get test results?
Typically several hours to a few days, depending on the laboratory and testing methods used.

What happens if bilirubin levels are abnormal?
May require further testing, medical evaluation, and potentially treatment to address underlying conditions.