Hyperkoagulering

Hyperkoagulering, or hypercoagulability, is a medical state in which the blood has an increased tendency to form clots. It is one of Virchow’s triad components, together with venous stasis and endothelial injury, and it can predispose to both venous and arterial thrombosis.

Causes are largely categorized as inherited or acquired. Inherited factors include mutations and deficiencies such as factor V Leiden, prothrombin G20210A, and deficiencies of protein C, protein S, or antithrombin. Acquired factors include malignancy, pregnancy and the postpartum period, use of estrogen-containing medications, obesity, smoking, prolonged immobilization, recent surgery or trauma, inflammatory or autoimmune diseases, and antiphospholipid syndrome.

Pathophysiology involves an imbalance between procoagulant and anticoagulant pathways, endothelial activation, and often reduced fibrinolysis. This promotes thrombus formation in veins and, less commonly, in arteries, depending on the underlying cause and context.

Clinical presentation varies. The most common consequence is venous thromboembolism, presenting as deep vein thrombosis or pulmonary embolism. Arterial thrombosis may occur, particularly with antiphospholipid syndrome or other high-risk conditions. In pregnancy, hyperkoagulering raises risks of fetal loss and maternal thrombosis. Some individuals with thrombophilia may have recurrent pregnancy loss or other pregnancy-related complications.

Diagnosis is guided by clinical risk assessment and history. Laboratory testing for thrombophilia is targeted and not routinely performed after all first events; when indicated, tests may include genetic assays for Factor V Leiden and prothrombin G20210A, functional assays for protein C, protein S, and antithrombin, and antiphospholipid antibody testing. Management revolves around anticoagulation for active thrombosis and, depending on risk, extended or indefinite therapy, with special considerations during pregnancy and in provoking scenarios. Risk factor modification is also important.