Fibrinogen Activity: (Cardiovascular risk / Inflammatory marker) Fibrinogen is a protein in your blood that helps with clotting and also acts as a marker of inflammation. This test measures how active fibrinogen is, which can give insight into cardiovascular risk and inflammation levels. Normal levels support healthy clotting and indicate balanced inflammation. High levels may suggest increased inflammation and a higher risk of heart disease, stroke, or clotting issues. Low levels are less common but can lead to problems with blood clotting.