hyperkoagulation

Hypercoagulation, also called hypercoagulability, is a state in which the blood has an increased tendency to form clots. It is a component of Virchow's triad of thrombogenesis, along with stasis and endothelial injury, and can affect veins or arteries.

Causes include inherited thrombophilias (Factor V Leiden, prothrombin G20210A, protein C or protein S deficiency, antithrombin deficiency) and acquired conditions (cancer, pregnancy and the postpartum period, estrogen-containing medications, obesity, recent surgery or trauma, prolonged immobility, smoking, inflammatory or autoimmune diseases, antiphospholipid syndrome).

Presentation usually involves venous thrombosis, such as deep vein thrombosis or pulmonary embolism; arterial events may occur, especially with certain conditions such as antiphospholipid syndrome or some myeloproliferative neoplasms.

Diagnosis relies on history and risk factor assessment, supported by laboratory testing for thrombophilia. Tests may include levels of protein C, protein S, and antithrombin; tests for activated protein C resistance (Factor V Leiden); and antibody testing such as lupus anticoagulant, anticardiolipin, and anti-beta-2 glycoprotein I. Imaging confirms the presence of thrombosis when indicated.

Management centers on treating the acute clot and reducing recurrence risk. Anticoagulation is commonly used, with options including unfractionated heparin, low-molecular-weight heparin, direct oral anticoagulants, or vitamin K antagonists. The duration of therapy depends on the underlying cause and recurrence risk; inherited conditions may require extended or lifelong treatment in some cases. Pregnancy requires specialized management to balance maternal and fetal considerations.

Prognosis varies with the underlying cause and access to appropriate prevention and treatment. In many cases, risk reduction focuses on addressing modifiable factors and, when indicated, employing thromboprophylaxis during high-risk periods.