Coagulation is the process by which liquid blood transforms into a solid or semi-solid state, forming a clot. This is a crucial mechanism that helps prevent excessive bleeding when injuries occur. The process involves various proteins in the blood, known as clotting factors, which work together to create a mesh of fibrin that traps blood cells and forms a stable clot. The coagulation process can be divided into three main stages: vascular spasm, platelet plug formation, and coagulation cascade. Initially, blood vessels constrict to reduce blood flow. Next, platelets adhere to the injury site and aggregate to form a temporary plug. Finally, the coagulation cascade activates, leading to the formation of fibrin and a more durable clot.