[Risk factors]

By entrances to facilities, injury, invasions of the operation, and complication as cancer, etc., a crisis risk remarkably increases on pulmonary embolism thrombosis(PE). As risk factors of thrombosis except for above, abnormal protein C, abnormal protein S and abnormal antithrombin are often observed. Caucasians have frequently FV Leiden or abnormal FII as congenital thrombophilia, though those are not observed to Japanese. As an acquired risk factor for PE, there are cancer, high homocysteinemia, lipid abnormality and anti-phospholipid antibody syndrome. It is necessary to evaluate these risk factors for the prevention of PE.