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.
Statistical Analysis of pulmonary embolism in india got the results as Radionuclide venography-detectable DVT was noted in 744 patients, of whom 521 (70%) had suprapopliteal DVT. Of patients with DVT, 294 (39.5%) showed a high-probability lung scan and 135 (18.1%) had an intermediate-probability lung scan. Overall, 47% of patients with a high-probability scan had no clinical manifestations suggestive of PE.