What is the term for the obstruction of blood vessels caused by a clot of blood or a foreign substance?

The term that specifically refers to the obstruction of blood vessels caused by a clot of blood or a foreign substance is embolism. An embolism occurs when an embolus, which can be a clot or other material, travels through the bloodstream and lodges in a vessel, blocking blood flow to a part of the body. This blockage can lead to serious complications, such as tissue damage due to lack of oxygen.

Thrombosis refers to the formation of a blood clot within a blood vessel, which can lead to obstruction but does not involve the travel of that clot through the bloodstream. Ischemia describes a condition where there's a decrease in blood flow to a tissue, often resulting from an obstruction, but it does not specifically denote the presence of an embolus. Stasis refers to stagnation of blood flow, which can lead to clots but is not synonymous with an obstruction caused by a traveling clot or foreign substance. Therefore, the definition of embolism fits the question precisely, as it highlights the mechanism and result of the obstruction.