How fast does a blood clot travel from the legs to the lungs?
A blood clot can break loose and travel from the legs to the lungs rapidly. It may take several days or weeks, or it can happen in a matter of minutes or hours. Once it has moved, a blood clot in the lungs can develop, which is known as an embolism. If the blood clot quickly cuts off blood supply, it is called an infarct.