Fibrinogen

Function

Fibrinogen, also known as Factor I, is a soluble plasma glycoprotein synthesized in the liver. It is a critical component of the coagulation cascade. When a blood vessel is injured, the enzyme thrombin converts fibrinogen into fibrin, which forms a fibrous mesh that stabilizes blood clots and stops bleeding. Beyond clotting, fibrinogen is an 'acute-phase reactant,' meaning its levels rise significantly in response to systemic inflammation or tissue injury.

Why it is Ordered

This test is primarily used to evaluate bleeding disorders or abnormal blood clotting events. It is ordered if a patient has unexplained or prolonged bleeding, frequent bruising, or as part of a workup for Disseminated Intravascular Coagulation (DIC). It is also used to assess the risk of cardiovascular disease, as chronically elevated levels are associated with increased arterial plaque formation.

Associated Conditions

• Hypofibrinogenemia: Low levels often seen in severe liver disease or malnutrition.
• Disseminated Intravascular Coagulation (DIC): A life-threatening condition where fibrinogen is consumed rapidly by widespread clotting.
• Hyperfibrinogenemia: High levels linked to acute infections, rheumatoid arthritis, or myocardial infarction.
• Afibrinogenemia: A rare congenital absence of fibrinogen causing severe bleeding tendencies.