Fibrinogen is one of the proteins present in the blood plasma. It makes 7% of the plasma proteins. During the process of blood clotting, the active thrombin enzyme serves to convert soluble fibrinogen into insoluble fibrin. These insoluble threads of fibrin form the clot. Both thrombin and fibrinogen are produced in the liver. If fibrinogen is less than 4%, the process of blood clotting will be disturbed due to the production of insufficient threads of fibrin.
