What causes pulmonary embolism

Pulmonary embolism is a group of diseases or clinical syndromes whose pathogenesis is caused by various emboli blocking the pulmonary artery or its branches. Pulmonary embolism is caused by pulmonary artery occlusion. The most common reason is the thrombosis formed in the deep vein of the leg, which falls off and transfers to the pulmonary artery and embeds in the pulmonary artery. In rare cases, pulmonary embolism may be caused by other substances, including: bacterial clumps gathered by microorganisms, called bacterial emboli. Free fat, after fracture, surgery, trauma or severe burns, fat particles may be released into the venous blood and eventually flow through the pulmonary artery to cause embolism. Amniotic fluid, bubbles or sundries enter blood vessels through wounds, surgery or medical devices. Cancer cells invade the vein and rapidly grow and fall off to form emboli, called tumor emboli.