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Bilirubin Test

⚠️ Update approaching🔬 Evidence: ModerateInternal Medicine
Diğer adları: Bilirubin level, Direct bilirubin, Indirect bilirubin
⚠️

Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.

⚡ Key Facts

• A breakdown product of hemoglobin, processed by the liver and excreted in bile • Total bilirubin includes direct (conjugated) and indirect (unconjugated) fractions • Elevated levels may cause jaundice (yellowing of skin and eyes) • The pattern of elevation helps identify the cause

🧪 What Does This Test Measure?

The bilirubin test measures a breakdown product of hemoglobin that is processed by the liver and excreted in bile, with elevated levels potentially causing jaundice.

📋 Why Is It Ordered?

Ordered for jaundice evaluation, liver function monitoring, bile duct obstruction investigation, and hemolytic anemia assessment.

🔧 Preparation

No special preparation is generally required. Prolonged fasting may elevate indirect bilirubin.

📊 Reference Ranges

Total bilirubin: 0.1–1.2 mg/dL (2–21 µmol/L) Direct bilirubin: 0–0.3 mg/dL Indirect bilirubin: 0.1–0.8 mg/dL ⚠️ Reference ranges vary by laboratory.

⬆️ High Values

Elevated bilirubin may be associated with liver disease, bile duct obstruction, hemolytic anemia, or Gilbert syndrome (a common benign condition).

⬇️ Low Values

Low bilirubin is generally not clinically concerning on its own.

⚙️ What Can Affect Results?

Fasting, hemolysis rate, liver function, bile duct patency, certain medications, and Gilbert syndrome may affect bilirubin results.

🔬 Evidence Summary

Moderate evidence: 2 guidelines.

📚 Most Important Studies on This Topic

1

ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries

Guideline· American Journal of Gastroenterology · 2017 · PMID: 27995906

2

EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis - 2021 update

Guideline· Journal of Hepatology · 2021 · PMID: 34166721

✅ Key Takeaways

💡

What you learned: Bilirubin elevation causes jaundice. The pattern — whether direct or indirect is elevated — helps guide evaluation.

⛔

A bilirubin result alone cannot diagnose the cause of jaundice. Liver function tests, imaging, and clinical context are needed.

🔬 Sources Used on This Page

2 sources · Most recent publication: 2021
📋
Guideline
Expert society and guideline recommendations
2
sources
Overall assessment: Evidence level for this topic is moderate. This page is supported by 2 guidelines.

📝 Questions to Ask Your Doctor

Be prepared for your appointment. Add questions to your list.

📋 References

[PMID: 34166721] EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis - 2021 update. Journal of Hepatology, 2021.
[PMID: 27995906] ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries. American Journal of Gastroenterology, 2017.
Last reviewed: 4/1/2026
Next review: 4/1/2027

🔗 Related Topics

🧪 ALT/AST (karaciğer enzimleri)🧪 GGT (gama-glutamil transferaz)🧪 ALP (alkalen fosfataz)🧪 Hemogram (hemoliz değerlendirmesi)
⚖️ This page does not replace medical advice. Make treatment decisions with your doctor.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.