triadhypercoagulability

Triad hypercoagulation is a conceptual framework used to describe how three interacting factors raise the risk of thrombosis. It is closely related to Virchow's triad, which identifies hypercoagulability, endothelial injury or dysfunction, and abnormal blood flow as the principal contributors to clot formation. In practice, triad hypercoagulation emphasizes that a prothrombotic state typically results from the combination of these elements rather than a single cause.

Hypercoagulability arises from genetic thrombophilias—such as Factor V Leiden, the prothrombin G20210A mutation, and deficiencies of protein C, protein S, or antithrombin—as well as acquired conditions like cancer, obesity, pregnancy, hormone therapy, and inflammatory diseases. Endothelial injury or dysfunction occurs with vascular injury, infections, inflammation, surgery, or radiation, which expose tissue factor and other procoagulant surfaces that promote clot formation. Abnormal blood flow includes venous stasis during immobility, turbulence from vascular disease, atrial fibrillation, or certain medical procedures, all of which facilitate platelet aggregation and coagulation cascade activation.

Clinically, the triad helps explain why thrombosis develops in certain contexts, including perioperative periods, cancer-associated thrombosis, pregnancy, and critically ill patients. Management focuses on risk factor modification and appropriate use of anticoagulant or antiplatelet therapy as indicated, with prophylaxis in high-risk scenarios. Evaluation typically relies on patient history and diagnostic imaging for thrombosis; thrombophilia testing is selective and often deferred to non-acute settings.

Prevention and prognosis depend on addressing the underlying risk factors, implementing mechanical and pharmacologic prophylaxis when appropriate, and treating established thrombi promptly. The concept remains a useful lens for understanding multimodal risks that contribute to clot formation. See also Virchow’s triad, thrombophilia, venous thromboembolism.