Medical Specialties: Emergency medicine, Internal medicine

Clinical Definition

A thromboembolism is the occlusion of blood flow in a vessel due to a thrombus. It can occur if a fragment of a thrombus travels through the bloodstream from the original site of formation and lodges in a blood vessel. The thrombus obstructs blood flow in the vessel. Various consequences, such as tissue death or infarction, can occur depending on what vessel is obstructed.      

In Our Own Words

A thromboembolism is the blockage of blood flow in a vessel due to a thrombus, or a type of blood clot. A blood clot can form somewhere in the body, such as the veins of the leg. Clots in veins may form due to several reasons, such as inactivity, blood clotting disorders and surgery. Another kind of thromboembolism comes from plaques in arteries (i.e., atherosclerotic plaques), which leads to thrombus formation.


Because of reduced blood flow, complications can occur, which will vary depending on where the blockage is located. For instance, when blood clots travel to brain, they can cause a transient ischemic attack (TIA) or even a stroke; when they lodge in the vessels that go to the lung, they can cause a pulmonary embolism.

Relevant Conditions
  • Atherosclerosis
  • Pulmonary embolism
  • Deep venous thrombosis (DVT)
  • Cardiovascular surgery
  • Hypercoagulable states (e.g., pregnancy, birth control pills or cancer)
Common Types
  • Venous thromboembolism
  • Pulmonary embolism
  • Atherosclerotic
Side Effects
  • Leg swelling, shortness of breath, irregular heart rate or chest pain (i.e., DVT/pulmonary embolism)
  • Confusion, numbness, trouble walking, seeing, speaking, paralysis or headache (i.e., stroke)
Share this article
  • Farzan S., MD. “The Concise Handbook of Respiratory Diseases, 4th Edition.” Prentice Hall 1997. Accessed September 2013.
  • Cleveland Clinic. “Pulmonary Embolism.” Accessed September 2013.
  • Centers for Disease Control and Prevention. National Center on Birth Defects and Developmental Disabilities. “Venous Thromboembolism (VTE).” 2012. Accessed September 2013.

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