Atherosclerosis is the hardening and narrowing of the arteries. It raises the risk of having heart attack and stroke.
High cholesterol, especially LDL (bad cholesterol), plays a major role in the development of atherosclerosis. Although genetics is an important factor in high cholesterol, other lifestyle factors contribute significantly too, such as overweight, physically inactive, having a diet with high saturated fat and cholesterol.
Atherosclerosis can start early in life and develop gradually.
The inner lining of a healthy artery is smooth and intact. But many factors (diabetes, high blood pressure, high cholesterol)Â can cause injury and damage of this lining, which triggers an inflammatory reaction.
White blood cells get into the damaged artery wall and form foam cells. They accumulate fat and cholesterol, as well as other substances, which eventually form atherosclerotic plaque.
These plaques get thicker and harder overtime and bulge into the bloodstream to reduce or block blood flow. When an atheroma ruptures, it can lead to heart attack or stoke.
Source: webmd.com
Also see: Atherosclerosis (2) — Conditions that worsen it.