According to MedlinePlus, the primary function of fibrinogen is to help form blood clots. This protein, which is measurable with a blood test, is made in the liver.
MedlinePlus indicates that excessive bleeding and poor clotting are sometimes symptoms that too little fibrinogen is being produced. If a test reveals that atypical amounts of fibrinogen are in the blood, there are several possible causes. For example, in disseminated intravascular coagulation, too much fibrinogen is used to form clots, which eventually leads to the body experiencing a deficiency. Occasionally, the liver simply does not produce enough fibrinogen. Some people are born with this trait, while others acquire it. Excess bleeding also uses up large amounts of fibrinogen.