What does thrombus mean?
A thrombus is a blood clot that develops inside a blood vessel or the heart. Unlike blood that flows normally, a thrombus consists of coagulated blood constituents that attach to the vessel wall or cardiac tissue and can partially or completely block circulation. The word is especially common in discussions of deep-vein thrombosis, arterial or venous clots, coronary disease, and stroke. In clinical writing, it is often distinguished from an embolus: a thrombus forms where it originates, while an embolus travels through the bloodstream before becoming lodged in another vessel. Although the general term blood clot is more widely understood, thrombus is the more precise term when discussing the formation, structure, or medical effects of a clot. Its Greek-derived vocabulary also connects it with terms such as thrombosis and thrombotic.
nounA thrombus is a blood clot that forms within a blood vessel or the heart and remains attached to the vessel wall or cardiac tissue. It may partially or completely obstruct blood flow.
- A mass of coagulated blood constituents formed within a blood vessel or the heart, usually attached to the vessel wall or cardiac tissue and capable of obstructing blood flow.
"An ultrasound confirmed a thrombus in the deep vein."
"An ultrasound confirmed a thrombus in the deep vein."
"The fatal pulmonary blockage had originated as a thrombus in a leg vein."
The standard plural in medical and scientific writing.
"The examination revealed two thrombi in the deep veins."
A thrombus is a clot that stays put—an embolus is one that travels.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thrombus come from?
The word comes through Latinized Greek from Greek θρόμβος (thrombos), meaning “clot” or “lump.” The related English medical vocabulary developed from this Greek root, including thrombosis, thrombotic, thrombocyte, and thrombopoiesis.
Related word forms
How thrombus is actually used
Thrombus is a formal medical term, used particularly in vascular medicine, cardiology, pathology, and related clinical contexts. Its plural is typically thrombi.
Easily confused with thrombus
A thrombus is a clot formed in place and attached to a vessel wall or cardiac tissue, whereas an embolus is a clot or other material that travels through the bloodstream and lodges elsewhere.