Fibrinogen

Fibrinogen is a soluble plasma glycoprotein produced by the liver that is essential for blood clotting. When activated by thrombin, it is converted into fibrin strands that form a mesh to stabilize the platelet plug and stop bleeding. Fibrinogen is also an acute‑phase reactant involved in inflammation and wound healing; abnormal levels can raise bleeding or thrombosis risk.

A high fibrinogen level usually signals inflammation or an acute-phase response and increases blood viscosity and clotting tendency. It’s linked to higher risk of thrombosis, heart attack, and stroke and can occur with infection, chronic inflammatory conditions, cancer, pregnancy, smoking, obesity, or liver disease. Evaluation targets underlying causes and cardiovascular risk; management may include treating inflammation, lifestyle changes, and physician-guided therapy.

Normal plasma fibrinogen in adults is about 200–400 mg/dL (2.0–4.0 g/L); some laboratories use ranges approximately 150–450 mg/dL. Levels below the reference suggest hypofibrinogenemia and bleeding risk; elevated fibrinogen may reflect inflammation, pregnancy, or increased thrombosis risk. Always interpret results alongside clinical context and lab-specific reference intervals. Age, pregnancy, and acute illness can alter levels.

Fibrin is a fibrous protein formed from fibrinogen during coagulation; it creates a mesh that stabilizes the platelet plug to stop bleeding. This fibrin network traps blood cells and microbes, provides a scaffold for wound healing and tissue repair, and helps seal damaged vessels. Later, fibrin is broken down by fibrinolysis to restore normal blood flow once healing progresses.

Low fibrinogen reduces the blood’s ability to form stable clots, causing easy bruising, prolonged bleeding after cuts, surgery or dental work, heavy menstrual bleeding, frequent nosebleeds, and increased risk of internal bleeding or postpartum hemorrhage. Very low levels can cause life‑threatening hemorrhage and poor wound healing. Laboratory tests show prolonged clotting times; treatment may include fibrinogen replacement or treating the underlying cause.

Yes. Psychological and physical stress can raise fibrinogen because it’s an acute‑phase protein that increases with inflammation and sympathetic activation. Short‑term stress causes transient rises; chronic stress and related behaviors (poor sleep, smoking, obesity) can sustain higher fibrinogen, raising cardiovascular risk. Persistently high levels prompt evaluation for infection, chronic inflammation and lifestyle factors, with stress reduction and medical management as appropriate.