This new edition is a comprehensive and updated resource on antiphospholipid syndrome (APS), which is an autoimmune disorder. In APS, the body recognizes certain normal components of blood and/or cell membranes as foreign substances and produces antibodies (antiphospholipid antibodies) against them. APS is associated with recurrent clotting events (thrombosis) including premature stroke, repeated miscarriages, phlebitis, venous thrombosis, and pulmonary thromboembolism. It is also associated with low platelet or blood elements that prevent bleeding. Recently, however, even more disease states have been linked with APS, including premature heart attack, various cardiac valvular abnormalities, skin lesions, kidney disease, abnormal involuntary movement/chorea, diseases that mimic multiple sclerosis, and vascular diseases of the eye that can lead to visual loss and blindness.