Acquired disorders of coagulation

Normal coagulation is a delicate balance between pro- and antithrombotic mechanisms. Haemorrhage results from dysfunctional/absent procoagulant mechanisms and can be caused by inherited or acquired factors. The most common acquired abnormalities seen in the clinical setting are covered in this article, including vitamin K deficiency, warfarin therapy, liver disease, direct oral anticoagulants, disseminated intravascular coagulation, platelet disorders and vascular disorders. Patients bleeding on warfarin therapy need urgent international normalized ratio testing and reversal with vitamin K and/or prothrombin complex concentrate. Patients bleeding while taking direct oral anticoagulants need a wider approach. Liver disease results in complex haemostatic changes, and the management of bleeding depends on the site and severity of bleeding. Disseminated intravascular coagulation can complicate many clinical situations and needs prompt action when patients are bleeding. Acquired dysfunction of platelets is commonly encountered in clinical practice, often in association with drug therapy such as aspirin.