Final answer:
Thrombosis is the medical term for a condition in which a mass, commonly a blood clot, obstructs blood flow in a blood vessel. It is caused by vessel damage and can occur in large or small vessels.
Step-by-step explanation:
The medical term for a condition in which a mass, commonly a blood clot, becomes lodged in a blood vessel, obstructing blood flow is thrombosis. Thrombosis occurs when a thrombus, an aggregation of platelets, erythrocytes (red blood cells), and even white blood cells, forms within an intact or slightly damaged blood vessel, obstructing blood flow. This condition can occur in large vessels as a mural thrombus or in small vessels as an occlusive thrombus. It is most commonly caused by vessel damage to the endothelial lining, which activates the clotting mechanism.