Coagulation system (Coagulation cascade)

The **coagulation system**, often referred to as the **coagulation cascade**, is a complex series of enzymatic reactions involving plasma proteins (mainly serine proteases, cofactors, and glycoproteins) that control blood clotting to achieve hemostasis[1][2][4][3][5]. The process is initiated by either the tissue factor (extrinsic) pathway or the contact activation (intrinsic) pathway, both converging on the common pathway leading to activation of factor X, formation of thrombin, and conversion of fibrinogen to insoluble fibrin, which forms the clot structure[1][3][4]. This cascade is tightly regulated to prevent both excessive bleeding and abnormal clot formation, and disturbances contribute to a wide range of bleeding and thrombotic diseases[2][4][3].

Other names

coagulation cascadeblood coagulationcoagulation pathwayblood clotting pathway

Inhibition of specific coagulation factors to prevent clot formation (e.g., warfarin inhibits vitamin K-dependent factors); Direct inhibition of thrombin or factor Xa (e.g., direct oral anticoagulants); Activation of fibrinolysis to dissolve clots (e.g., tPA increases conversion of plasminogen to plasmin); Factor replacement to restore deficient factors in hemophilia.