A fibrinogen activity test is also known as a Factor I Activity. 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.The normal range is 200 to 400 mg/dL (2.0 to 4.0 g/L). Elevated fibrinogen levels

increase the risk of blood clots, which can, in turn, contribute to an increased risk of heart

disease. High fibrinogen is associated with higher rates of heart disease, blood vessel

dysfunction, and stroke.