What is the term for the obstruction of a blood vessel, often by a clot?

• A. Stenosis
• B. Embolism
• C. Thrombosis
• D. Occlusion

Answer: (B)

The term for the obstruction of a blood vessel, often by a clot, is embolism. An embolism specifically refers to a situation where an embolus, which can be a blood clot, air bubble, fat deposit, or other debris, travels through the bloodstream and lodges in a blood vessel, obstructing blood flow. This obstruction can occur in various parts of the body and can lead to serious health complications, such as stroke or pulmonary embolism, depending on the site of the blockage.

In contrast, thrombosis refers to the formation of a blood clot within a blood vessel at the site of the vessel itself, which is related but distinct from embolism, as thrombosis describes the process rather than the state of obstruction by a traveling clot. Stenosis refers to the narrowing of a blood vessel, typically due to plaque buildup, which is different from an obstruction caused by a clot. Occlusion generally describes the blockage of a blood vessel but is a broader term that can include both embolism and thrombosis, thus not specifically identifying the traveling aspect of an obstruction.