This document discusses antiphospholipid antibody syndrome (APS), a condition characterized by vascular thrombosis and/or pregnancy morbidity in the presence of antiphospholipid antibodies. It covers the etiology, pathogenic mechanisms, diagnostic criteria, clinical manifestations, and treatment principles for APS. Key points include that APS is the most common acquired thrombophilia, can be primary or secondary to other conditions like SLE, is diagnosed based on both clinical and laboratory criteria including positive tests for lupus anticoagulant, anticardiolipin antibodies, or anti-beta 2 glycoprotein I antibodies, and treatment involves anticoagulation and immunosuppression.