The main cause of CVD is atherosclerosis—the build up ofplaque inside the blood vessel walls.
Plaque consists of cholesterol, fat, and macrophages (a type of white blood cell).
Other substances like calcium may also be present.
The vessels become narrow or even completely blocked up, so little or no blood can travel through to the brain, heart and other organs.
The narrower the artery, the greater the risk of them being blocked by a rupture in the plaque-lined artery wall or a blood clot.
About 10% of heart attacks result from blockages directly related to the accumulated hard plaques.
The greater risks—and those leading to as many as 90% of heart attacks—are those of softer plaques, deposits of which are linked to higher cholesterol and are more unstable so more likely to rupture and block blood flow to the heart muscle or brain.6
These dangerous soft plaques often go unnoticed, even in angiograms.
We’re born with clean and flexible arteries that have the capacity to stay that way over time.
However a very early study observed that most of the young people studied, who were around 20 years old, had plaque deposits taking up 20% of the internal space in their blood vessels (the arterial lumen).7
Typically, by the time many of us are 45 years of age, plaque can have grown to the point that it narrows our arterial lumen by 50% or more in many people. And by 70 years of age, many live with up to 90% narrowing of some of their arteries, leaving only 10% opening for blood to flow through.7
But how does atherosclerosis happen? It’s a process with many contributing factors.