How does atherosclerosis develop?
Although the exact process is not completely understood, scientists
have described three different stages of atherosclerosis that lead to clogged
arteries. These stages do not necessarily occur in order, nor is there always a
progression from one stage to the next.
The fatty streak
The first evidence of atherosclerosis can be found in children 10
to 14 years old. The "fatty streak" appears as a yellow streak running inside
the walls of the major arteries, such as the aorta. The streak consists of
cholesterol, white blood cells, and other cellular matter. The fatty streak by
itself does not cause symptoms of heart disease but can develop into a more
advanced form of atherosclerosis, called fibrous plaque.
The plaque
A plaque forms in the inner layer of the artery. The plaque
consists of large numbers of cells that are filled with cholesterol. When a
plaque grows in the artery, it may block blood flow, causing the symptoms of
stable angina.
Complicated lesion
The last stage of atherosclerosis occurs when the plaque breaks
open, exposing the cholesterol and tissue underneath. Blood clots form in
response to this rupture and cause symptoms of a heart attack and unstable
angina.