Definition
What is an embolism?
An embolism is the sudden plugging of a vessel by an embolus, a mass that rides along in the bloodstream until it reaches a vessel too narrow to pass. Most emboli are pieces of a blood clot (thrombus) that broke away from where it formed, but an embolus can also be a bubble of air, droplets of fat, amniotic fluid, a clump of tumor cells or infected material.
Where the embolus lodges decides the damage. Clots from the deep veins of the legs or pelvis travel through the right side of the heart and stick in the arteries of the lungs, causing a pulmonary embolism, with chest pain, breathlessness and sometimes death. Clots that form in the heart, for example during atrial fibrillation, can be carried to the brain and cause an ischemic stroke. Tissue beyond the blockage is starved of oxygen and may die, forming an infarct.
Thrombosis and embolism are easy to confuse. Thrombosis is a clot forming in place; embolism is material that has traveled and blocked a vessel somewhere downstream. Because the two so often occur together, clots in the veins and the emboli they release are grouped as venous thromboembolism.
Word parts
Where does the word “embolism” come from?
- embol-
- something thrown in; a plug or wedgeGreek embolos, from emballein (to throw in)
- -ism
- a conditionGreek -ismos
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Terms that go with it
- ThrombosisThrombosis is the formation of a blood clot, called a thrombus, inside a blood vessel or the heart, where it can narrow or block the flow of blood.
- StrokeA stroke is a sudden loss of brain function that happens when an artery supplying the brain is blocked or bursts and bleeds.
- InfarctionInfarction is the death of an area of tissue, called an infarct, caused by a sudden loss of its blood supply, as in a heart attack or a stroke.
- IschemiaIschemia is a shortage of blood supply to an organ or tissue, usually from a narrowed or blocked artery, that starves its cells of oxygen and nutrients.
- PlateletA platelet is a small cell fragment in the blood that helps stop bleeding by plugging damaged vessels and helping a blood clot form.
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Written for biofideX in plain words, after checking these references:
- OpenStax Anatomy and Physiology 2e, 18.5 Hemostasis
- MedlinePlus Medical Encyclopedia: Pulmonary embolus
- MedlinePlus: Ischemic Stroke
- NCBI MeSH: Embolism
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