what is fibrinogen

Fibrinogen is a blood plasma protein that is produced by the liver and is important for blood clotting. It is one of 13 coagulation factors responsible for normal blood clotting. When you start to bleed, your body initiates a process called the coagulation cascade, or clotting cascade. This process causes coagulation factors to combine and produce a clot that stops the bleeding. Fibrinogen is a major structural component of a clot. A fibrinogen test measures the level of fibrinogen in your blood. The test is also called the factor I activity test, serum fibrinogen, and functional fibrinogen test. Low levels of fibrinogen can cause excessive bleeding, and if you have low fibrinogen, you may have intravenous (IV) treatments to increase your levels. A typical fibrinogen level is between 2 and 4 grams per liter or 200 to 400 milligrams per deciliter. A fibrinogen activity test may be ordered alone or as part of a series of tests to determine the cause of abnormal bleeding. Your doctor may order a fibrinogen activity test if you’re experiencing excessive bruising, excessive bleeding from the gums, frequent nosebleeds, hemorrhage of the gastrointestinal tract, blood in the urine, blood in the stool, bleeding in the head, rupture of the spleen, or other symptoms.