Fibrinogen: Functions, Normal Levels, and Interpretation

What Is Fibrinogen?

Fibrinogen is a protein produced in the liver that plays a crucial role in blood clotting. This biomarker helps form blood clots to stop bleeding after an injury. 

It helps form fibrin, a vital part of the clotting process.

Healthcare professionals use fibrinogen levels to assess clotting disorders and diagnose underlying health issues, including inflammation, liver disorders, and cardiovascular conditions. 

When Is Fibrinogen Testing Recommended?

Doctors recommend fibrinogen testing to evaluate blood clotting ability and detect abnormalities. This test can be part of routine health check-ups or prescribed for specific symptoms and conditions.

Situations requiring a fibrinogen test include:

• High blood pressure.
• Unexplained or prolonged bleeding.
• Suspected thrombosis or abnormal clot formation.
• Abnormal results in other clotting tests like PT (Prothrombin Time) or PTT (Partial Thromboplastin Time).
• Symptoms of disseminated intravascular coagulation (DIC).
• Monitoring treatment for clotting or fibrinolysis disorders.
• Suspected inherited or acquired clotting factor deficiencies.
• Pre-surgery evaluation to minimize bleeding risks.

Regular testing helps monitor ongoing treatment and detect potential complications early.

How Is Fibrinogen Testing Conducted?

Healthcare providers measure fibrinogen levels using a blood test. They collect a small sample from a vein, typically from the arm. 

Fibrinogen is often tested as part of a coagulation panel that may include prothrombin time (PT) and partial thromboplastin time (PTT). These tests assess clotting functions and detect related abnormalities.

Test Preparation

• Avoid eating for at least 8 hours before the test; drink only water.
• Refrain from alcohol consumption 24 hours before the test.
• Avoid smoking for 30 minutes before the test.
• Minimize physical and emotional stress before sample collection.

Proper preparation ensures accurate and reliable results.

What Are the Normal Fibrinogen Levels?

Normal fibrinogen levels vary by age, health status, and physiological conditions. For adults, the typical range is 2 to 4 g/L.

During pregnancy, levels naturally increase to support the body’s clotting needs. Values can range depending on the trimester:

• Less than 14 weeks: 2.12–4.33 g/L
• 21 weeks: 2.9–5.3 g/L
• 29 weeks: 3.0–5.7 g/L
• 35 weeks: 3.2–5.7 g/L
• 42 weeks: 3.5–6.5 g/L

Note: Units and normal ranges may vary between laboratories and testing methods. Consult your healthcare provider for precise interpretation

What Do Abnormal Levels Mean?

Fibrinogen High Levels

Elevated fibrinogen levels can increase the risk of dangerous blood clots that may affect your heart or brain.

Common causes include:

• Inflammatory diseases: Chronic inflammation raises fibrinogen production.
• Pregnancy: Natural increase supports clotting during this period.
• Thrombosis: Blood clots in veins or arteries elevate fibrinogen.
• Cardiovascular conditions: Coronary artery disease and heart attack involve higher levels.
• Stroke: Increased fibrinogen links to clot-related strokes.
• Trauma or burns: Tissue damage triggers an acute rise.
• Cancer: Certain cancers stimulate fibrinogen production.

• Discuss results with your doctor to identify underlying causes.
• Maintain a healthy weight through regular exercise.
• Avoid smoking and second-hand smoke exposure.
• Eat a balanced diet rich in fruits, vegetables, and lean proteins.
• Limit alcohol consumption.
• Consider supplements as recommended by a healthcare professional.

Fibrinogen Low Levels

Reduced fibrinogen levels can impair blood clotting and increase bleeding risks. Common causes include:

• Liver diseases: Impaired production due to liver dysfunction.
• Congenital disorders: Conditions like afibrinogenemia or hypofibrinogenemia.
• Cryofibrinogenemia: Rare disorder involving abnormal fibrinogen behavior.
• Disseminated intravascular coagulation (DIC): Excessive clotting depletes fibrinogen.
• Snake venom poisoning: Certain venoms degrade fibrinogen.
• Acquired dysfibrinogenemia: Abnormal fibrinogen structure due to disease.

• Seek medical advice to address the root cause.
• Follow a liver-friendly diet, avoiding processed foods and high-fat meals.
• Stay hydrated and avoid excessive alcohol.
• Monitor symptoms like unusual bleeding or bruising closely.
• Consider regular follow-ups with your doctor.

Which Specialist Should You Consult?

For fibrinogen-related issues, consult a healthcare professional based on your symptoms and medical history:

• General practitioner: Initial evaluation and routine check-ups.
• Cardiologist: For heart and vascular concerns.
• Hepatologist: If liver dysfunction is suspected.
• Hematologist: For blood disorders and coagulation issues.
• Surgeon: Pre-operative evaluations.
• Gynecologist: During pregnancy or related conditions.