- Blood clotting disorders, also called coagulation disorders or coagulopathies, are medical conditions that disrupt the normal balance between clot formation (coagulation) and clot breakdown (fibrinolysis).
- In healthy individuals, the coagulation system functions as a tightly regulated cascade of events that stops bleeding when a blood vessel is injured, while preventing excessive clot formation that could obstruct blood flow. When this balance is disturbed, the result can be either excessive bleeding due to insufficient clot formation, or excessive clotting (thrombosis) due to uncontrolled coagulation. These disorders can be inherited or acquired, and their severity ranges from mild to life-threatening.
- Bleeding disorders occur when there is a deficiency or dysfunction of clotting factors, platelets, or other components necessary for normal hemostasis. Inherited bleeding disorders include hemophilia A (factor VIII deficiency), hemophilia B (factor IX deficiency), and von Willebrand disease (deficiency or dysfunction of von Willebrand factor). These conditions lead to prolonged bleeding after injury or surgery, easy bruising, spontaneous joint or muscle bleeding, and, in severe cases, life-threatening hemorrhage. Acquired bleeding disorders may result from liver disease (which reduces clotting factor production), vitamin K deficiency, certain medications such as anticoagulants, or immune-mediated destruction of platelets, as in immune thrombocytopenic purpura (ITP).
- Clotting (thrombotic) disorders occur when the body forms blood clots inappropriately, even in the absence of injury. These can cause dangerous blockages in veins (venous thrombosis, such as deep vein thrombosis and pulmonary embolism) or arteries (arterial thrombosis, which can lead to heart attack or stroke). Inherited thrombophilias include Factor V Leiden mutation, prothrombin gene mutation, and deficiencies of natural anticoagulants such as protein C, protein S, and antithrombin. Acquired causes of thrombophilia include prolonged immobility, surgery, cancer, pregnancy, hormonal contraceptive use, and certain autoimmune diseases such as antiphospholipid syndrome. Some thrombotic disorders, such as thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC), are complex syndromes involving widespread activation of clotting, often with secondary bleeding due to consumption of platelets and coagulation factors.
- Diagnosis of blood clotting disorders depends on a detailed medical history, family history, physical examination, and laboratory tests. These may include platelet counts, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen levels, D-dimer levels, and specific clotting factor assays. In suspected inherited disorders, genetic testing can confirm the underlying mutation.
- Treatment varies depending on whether the disorder causes bleeding or thrombosis. For bleeding disorders, therapy may involve replacement of the missing clotting factor (as in factor VIII or IX concentrates for hemophilia), desmopressin (for some forms of von Willebrand disease), antifibrinolytic agents, or platelet transfusions. For clotting disorders, treatment focuses on anticoagulants such as heparin, warfarin, or direct oral anticoagulants to prevent or dissolve clots, along with measures to address the underlying cause. In some cases, long-term or lifelong anticoagulation may be necessary.
- Because the coagulation system is closely linked to inflammation, vascular health, and the immune system, blood clotting disorders often overlap with other medical conditions. A careful, individualized approach is essential to balance the risks of bleeding and clotting, both during acute treatment and in long-term management. Advances in molecular genetics, targeted biologics, and point-of-care coagulation testing continue to improve outcomes for patients with these complex and potentially life-threatening disorders.
