The fibrinogen activity test is also known as a Factor I assay. It’s used to determine the level of fibrinogen in your blood.
Fibrinogen, or factor I, is a blood plasma protein that’s made in the liver. Fibrinogen 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 will stop the bleeding. If you don’t have enough fibrinogen or if the cascade isn’t working normally, clots will have difficulty forming. This can cause excessive bleeding.
- A normal value for fibrinogen is between 200 and 400 mg/dL.
- A fibrinogen value of less than 50 mg/dL may mean you’re in danger of bleeding after surgery.
- A fibrinogen value of more than 700 mg/dl may mean you’re in danger of forming clots that could harm your heart or brain.
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