The antiphospholipid syndrome (APS) is an autoimmune disorder characterized by arterial or venous thrombosis, recurrent loss of pregnancy, and thrombocytopenia combined with laboratory tests that indicate the presence of antibodies against phospholipid-binding proteins. Clinically relevant APL antibodies are mainly anticardiolipin antibodies detected by solid-phase enzyme-linked immunosorbent assay and lupus anticoagulants demonstrated by in vitro coagulation assay. The condition can cause significant morbidity and even mortality. The term “APS” was first coined to denote the clinical association between antiphospholipid antibodies and a syndrome of hypercoagulability. Venous thrombosis occurs mostly in the lower limbs, with or without pulmonary embolism, and cerebral ischemia and transient ischemic attacks are the most common arterial events.