Fibrinogen

The final clotting protein — also an acute-phase inflammatory marker.

What it is

Fibrinogen is a plasma protein synthesised by the liver that is converted to fibrin to form blood clots. It is also an acute-phase reactant, rising with inflammation or infection.

Why it matters

Low fibrinogen (below 1.5 g/L) creates a clinically significant bleeding risk and can occur with disseminated intravascular coagulation (DIC) — a rare but serious clotting disorder associated with some cancers and infections. High fibrinogen is an independent cardiovascular and inflammatory risk marker.

How to test

Coagulation panel blood test.

This information is for educational purposes only. Always discuss testing and interpretation of results with your care team.

Optimal range

Below 1.5 g/L

critical — significant bleeding risk, possible DIC

2.0–4.5 g/L

normal

Above 4.5 g/L

elevated — may reflect inflammation

How often

Each comprehensive panel, or if clotting abnormalities are suspected.