title: The hypercoagulable states.
abstract: Patients are considered to have hypercoagulable states if they have laboratory abnormalities or clinical conditions that are associated with an increased risk of thrombosis (prethrombotic states) or if they have recurrent thrombosis without recognizable predisposing factors (thrombosis-prone). The number of specific primary hypercoagulable states that are recognized is growing. These disorders are generally inherited abnormalities of coagulation in which a physiologic anticoagulant mechanism is defective: for example, antithrombin III deficiency, protein C and protein S deficiency, abnormalities of the fibrinolytic system, and dysfibrinogenemias. Secondary hypercoagulable states are generally acquired disorders in patients with underlying systemic diseases or clinical conditions known to be associated with an increased risk of thrombosis: for example, malignancy, pregnancy, use of oral contraceptives, myeloproliferative disorders, hyperlipidemia, diabetes mellitus, and abnormalities of blood vessels and rheology. The complex pathophysiologic features of these secondary hypercoagulable states are discussed, and a framework is provided for the laboratory investigation and systematic clinical approach to the patient.
authors.forename: A I
authors.initials: AI
authors.lastname: Schafer
mesh_terms: D020152:Antithrombin III Deficiency; D001157:Arterial Occlusive Diseases / Q000150:complications; D001672:Biocompatible Materials; D001778:Blood Coagulation Disorders / Q000097:blood / Q000503:physiopathology*; D001779:Blood Coagulation Factors / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000502:physiology; D001809:Blood Viscosity; D003276:Contraceptives, Oral / Q000009:adverse effects; D048909:Diabetes Complications; D005175:Factor XII Deficiency / Q000503:physiopathology; D005260:Female; D005340:Fibrinogen / Q000502:physiology; D005342:Fibrinolysis; D006023:Glycoproteins / Q000172:deficiency; D006457:Hemoglobinuria, Paroxysmal / Q000150:complications; D006712:Homocystinuria / Q000150:complications; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications; D016682:Lupus Coagulation Inhibitor; D009196:Myeloproliferative Disorders / Q000150:complications; D009369:Neoplasms / Q000150:complications; D009404:Nephrotic Syndrome / Q000150:complications; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000503:physiopathology; D011486:Protein C; D017293:Protein S; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications; D013921:Thrombocytopenia / Q000150:complications; D013922:Thrombocytosis / Q000150:complications; D013923:Thromboembolism / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D014657:Vasculitis / Q000150:complications; D014689:Venous Insufficiency / Q000150:complications
chemical_list: D001672:Biocompatible Materials; D001779:Blood Coagulation Factors; D003276:Contraceptives, Oral; D006023:Glycoproteins; D016682:Lupus Coagulation Inhibitor; D011486:Protein C; D017293:Protein S; C025667:prothrombin complex concentrates; D005340:Fibrinogen