Internally Peer Reviewed Our blood normally flows continuously without clotting.
Immobility is the chief cause of leg vein clots which can loosen and fly to the lung.
Loose clots are called emboli, the Greek name for plugs. Prolonged travel, lying anesthetized on the operating table for surgery, or prior damage to the veins can interfere with the free flow of blood and cause clots that can endanger your life. If you don't want to die, it is nice to know how to avoid it. Large clots that kill by breaking off and blocking blood to the lungs usually form in the legs, particularly the thigh region. Smoking, cancer, and some hereditary blood clotting problems will add to the danger.