Bilirubin, Indirect

Bilirubin, Indirect 

Indirect bilirubin, also known as unconjugated bilirubin, is a type of bilirubin that is not yet processed by the liver. It is formed when red blood cells break down and release hemoglobin, which is then converted into bilirubin. Indirect bilirubin circulates in the bloodstream bound to albumin and is transported to the liver, where it is converted into direct (conjugated) bilirubin. 

1. What Does It Measure? 

• Indirect (unconjugated) bilirubin is measured by subtracting direct bilirubin from total bilirubin levels. 
• Elevated levels of indirect bilirubin may indicate increased red blood cell breakdown or problems with bilirubin processing in the liver. 

2. Why Is the Test Performed? 

This test helps: 
• Evaluate jaundice (yellowing of skin or eyes). 
• Diagnose hemolytic anemia and other causes of increased red blood cell destruction. 
• Assess liver function and distinguish between different types of liver diseases. 

3. Interpreting Results 

🔹 Normal Range: Approximately 0.2–0.8 mg/dL (may vary by lab). 
🔹 Elevated Indirect Bilirubin: 
• Hemolytic anemia 
• Gilbert’s syndrome (a benign liver condition) 
• Neonatal jaundice 
• Impaired bilirubin conjugation due to liver disease 

4. What Can Affect Levels? 

• Liver diseases (e.g., hepatitis, cirrhosis) 
• Genetic disorders (e.g., Gilbert’s syndrome, Crigler-Najjar syndrome) 
• Hemolysis (increased destruction of red blood cells) 
• Certain medications or infections 

5. How Is the Test Performed? 

• A blood sample is drawn from a vein. 
• No fasting or special preparation is typically needed. 

6. When to See a Doctor 

🚨 Speak with your healthcare provider if you: 
• Have symptoms of jaundice, fatigue, or dark urine. 
• Have a known blood or liver disorder. 
• Receive abnormal bilirubin results requiring further testing. 

🔹 Key Takeaways 

✅ Indirect bilirubin helps diagnose red blood cell or liver disorders. 
✅ High levels may indicate increased cell breakdown or impaired liver processing. 
✅ Results should always be interpreted alongside direct and total bilirubin values.