What do we call a blood clot that is attached to the interior wall of a blood vessel?

A blood clot that is attached to the interior wall of a blood vessel is referred to as a thrombus. This term specifically describes the condition in which the clot forms within a blood vessel and adheres to the vessel wall, which can interfere with normal blood flow. The formation of a thrombus is a critical aspect of hemostasis, the process involving blood clotting to prevent excessive bleeding.

In contrast, other terms refer to different conditions or mechanisms. For example, an embolus is a clot or other debris that has traveled through the bloodstream from its original site to another location, where it can lodge in a vessel and obstruct blood flow. Intravenous clot is not a standard term used in medical terminology, as it does not specifically convey the mechanism of attachment and formation. Thrombosis is the general process of clot formation that can lead to a thrombus but does not specifically identify the clot itself as being attached to the vessel wall. Therefore, "thrombus" is the precise term for a blood clot that remains attached to the vessel wall, distinguishing it from other related concepts.