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Fibrinogen Test
✅ Up to date🔬 Evidence: ModerateHematology
Diğer adları: Factor I, Fibrinogen level, Fibrinogen test
⚠️
Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.
⚡ Key Facts
• The key clotting protein (Factor I) involved in clot formation
• Also an acute phase reactant — rises with inflammation
• Normal: approximately 200–400 mg/dL
• Critical low: <100 mg/dL — serious bleeding risk
🧪 What Does This Test Measure?
The fibrinogen test measures the level of fibrinogen (Factor I), the key clotting protein that forms the structural framework of blood clots and also rises as an acute phase reactant.
📋 Why Is It Ordered?
Ordered for bleeding disorder evaluation, DIC investigation, and preoperative clotting assessment.
🔧 Preparation
Fasting is generally not required. Blood is collected in a citrated tube. Result turnaround time may vary.
📊 Reference Ranges
Normal: approximately 200–400 mg/dL (2.0–4.0 g/L)
Critical low: <100 mg/dL — serious bleeding risk
⚠️ Reference ranges vary by laboratory.
⬆️ High Values
Elevated fibrinogen may be associated with inflammation, infection, pregnancy, smoking, or obesity. It is an acute phase reactant.
⬇️ Low Values
Low fibrinogen may be associated with DIC, advanced liver disease, massive bleeding, thrombolytic therapy, or rare inherited deficiencies.
⚙️ What Can Affect Results?
Inflammation, pregnancy, liver function, medications, assay method, and smoking may affect fibrinogen results.
🔬 Evidence Summary
Moderate evidence: 2 guidelines and 2 reviews.
✅ Key Takeaways
💡
What you learned: Fibrinogen is essential for clot formation and also rises with inflammation. Very low levels indicate serious bleeding risk.
⛔
A fibrinogen result alone cannot diagnose a clotting or bleeding disorder. Clinical context and additional tests are needed.
🔬 Sources Used on This Page
4 sources · Most recent publication: 2024📋
Guideline
Expert society and guideline recommendations
2
sources
📖
Review
Comprehensive topic evaluation
2
sources
Overall assessment: Evidence level for this topic is moderate. This page is supported by 2 guidelines, 2 reviews.
📝 Questions to Ask Your Doctor
Be prepared for your appointment. Add questions to your list.
Last reviewed: 4/2/2026
Next review: 7/2/2026
⚖️ Comparisons
🔗 Related Topics
🧪 PT/INR (protrombin zamanı)🧪 aPTT (aktive parsiyel tromboplastin zamanı)🧪 D-dimer🧪 CRP (C-reaktif protein)🧪 Hemogram (trombosit sayısı)
⚖️ 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.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.