What are the most common causes of a pulmonary embolism?

DVT: The most common cause of a pulmonary embolism is deep venous thrombosis . Dvt usually occurs in individuals with trauma , hypercoagulable state, or immobilization. In individuals who have a DVT risk of pe can be 30% without treatment. If the DVT is treated risk of pe is substantially less

Clot to lungs: Blood clots from veins in the pelvis, legs, even arms and heart can "move" = embolize to other areas most commonly the lungs which receive all the blood circulation from the veins and the lungs ate a great filter to trap and clean up smaller emboli. Other things can embolize but this is the most frequent.

Few things: Recent surgery, prolonged immobilization, long distance traveling, cancer, smoking and blood disorders.