Fibrinogen is a protein found in the blood that plays a critical role in the clotting process. A fibrinogen test measures the amount of fibrinogen present in the blood, which can help diagnose and monitor various conditions related to blood clotting. The test is commonly used to evaluate patients with bleeding disorders or thrombotic disorders, such as deep vein thrombosis (DVT) or pulmonary embolism. High levels of fibrinogen can increase the risk of blood clots, while low levels can increase the risk of bleeding. In addition to diagnosing these conditions, the fibrinogen test can also be used to monitor the effectiveness of treatments such as anticoagulant therapy or surgery. The test is typically done by drawing a blood sample from a vein and is a simple and relatively non-invasive procedure.