Pulmonary embolism is a sudden blockage in a lung artery. Blockage usually is caused by a blood clot that travels to the lung from a vein in the leg. Because pulmonary embolism almost always occurs in conjunction with deep vein thrombosis, most doctors refer to the two conditions together as venous thromboembolism. Pulmonary embolism can be life-threatening, but prompt treatment can greatly reduce the risk of death. The incidence of pulmonary embolism was 4.8 cases per million for those traveling more than 10,000 km (6000 mi).
Disease Statistics of pulmonary embolism around France got the result as a total of 135.29 million passengers from 145 countries or other areas arrived at Charles de Gaulle Airport during the period of the study, of whom 56 had confirmed pulmonary embolism. The incidence of pulmonary embolism was much higher among passengers traveling more than 5000 km (3000 mi) (1.5 cases per million, as compared with 0.01 case per million among those traveling less than 5000 km).