Embolism refers to the occlusion of a blood vessel by an embolus (mass) that moves down the bloodstream and gets lodged in a blood vessel, causing circulation problems.
In Our Own Words
An embolism is when an embolus, which is a clump, bubble or mass, gets stuck in the bloodstream and causes a blockage. Embolisms are almost always from a blood clot but other types of emboli are also possible (a fat mass, a foreign body, etc.).
Perhaps the most significant and feared type of embolism is the pulmonary embolism (PE). In a PE, the blood clot typically forms in the veins of the legs, then breaks off and travels to the heart or lodges in the blood vessels of the lungs.