Fibrinogen

Coagulation factor tests are blood tests that check one or more of your clotting factors to see if you have too much or too little of a clotting factor, are missing a clotting factor, or have a clotting factor that isn't working right.

Your liver makes most of your clotting factors, including fibrinogen. Fibrinogen is also an 'acute-phase' protein, which means its level naturally goes up during inflammation, infection, pregnancy, or after an injury or surgery.

Lower than normal fibrinogen can lead to bleeding problems. It can be caused by rare inherited conditions, severe liver disease, malnutrition, or a serious clotting problem in which the body uses up clotting proteins faster than it can make them (called disseminated intravascular coagulation or DIC).

Higher than normal fibrinogen is often a sign of inflammation, infection, recent surgery, pregnancy, or estrogen use rather than a true clotting disorder. Levels that stay high over time have been linked to a higher long-term risk of blood clots in arteries and veins.

Because fibrinogen rises with inflammation, your provider will usually look at your result alongside other tests and your symptoms, not on its own.