Thrombus

A thrombus, also called a blood clot, is the final product of the coagulation step in hemostasis. There are two parts to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein.

Thrombus
Other names	Blood clot
Diagram of a thrombus (blood clot) that has blocked a blood vessel valve
Specialty	Vascular surgery

The substance making up a thrombus is sometimes called cruor.

A thrombus is a healthy response to injury to prevent bleeding, but can be harmful in thrombosis, when clots block blood flow through healthy blood vessels.