Plasminogen is a protein found in the blood that plays a crucial role in the body's ability to break down blood clots. It is produced by the liver and circulates in an inactive form. When a clot forms, plasminogen is activated to become plasmin, an enzyme that dissolves fibrin, the main component of blood clots. The activation of plasminogen is essential for maintaining proper blood flow and preventing excessive clotting, which can lead to conditions like thrombosis. This process is part of the body's natural healing mechanism, allowing for the removal of clots after they have served their purpose in stopping bleeding.