Atheroma

However, an atheromatous plaque may not always develop gradually; it can also rupture suddenly. When the plaque ruptures, the blood-clotting process is triggered. It starts with specific blood cells, called platelets, accumulating at the rupture point. The platelets and the fatty content of the plaque can then become detached and block an artery with a smaller diameter, which is what is called an embolism. Or a blood clot can form on the plaque itself and suddenly block the artery; this is known as thrombosis.

The formation of atheromatous plaques is a form of ageing of the arteries.

Arteriosclerosis is another form of ageing where the arteries thicken and become less supple.
These two processes combine to form atherosclerosis.
Atherosclerosis starts very early in adolescence and in theory only progresses very slowly.
Several factors, which are the cardiovascular risk factors, can accelerate the process and lead to premature ageing of the arteries.

The atheromatous plaques, above all when they rupture, cause most cardiovascular accidents, either by obstructing an artery where plaque is situated, or because of an embolism of vessels in an artery located further along the bloodstream. This can occur in a coronary artery (acute coronary syndrome), in a cerebral artery (ischemic cerebrovascular accident), or in the artery of a limb (acute ischaemia of a limb).