What causes a blood sample to clot?
Vials with no anticoagulant
Sample forgotten on the test bench
A blood clot is called a Thrombosis a blockage of a blood vessel by a blood clot. It is most likely to happen where normal blood flow is disrupted by for example plaques of fatty atheromatous tissue in the walls of an artery or inflammation of the blood vessel. The clot eventually narrows or blocks the passage of blood causing the tissues beyond to be starved of oxygen and nutrients.