Atherosclerosis

Atherosclerosis begins when cholesterol-carrying particles cross the artery wall and are retained there, triggering an inflammatory response. Immune cells take up the lipid, plaque forms, and the artery narrows and stiffens. It develops silently over decades, and can begin in early adulthood.

It matters because it is the underlying disease behind most heart attacks and many strokes. The acute event usually comes not from gradual narrowing but from a plaque rupturing and a clot forming on it, which is why a plaque that never caused symptoms can still be fatal.

In practice the recognised drivers are ApoB-containing lipoproteins, high blood pressure, smoking, diabetes and, in Lp(a), a largely genetic contribution. It is not simply an ageing process — the risk factors are substantially modifiable, and the earlier they are addressed the more the cumulative exposure is reduced.