Atherosclerosis - The fatal plug in your arteries

Dateline: 07/06/97

How is an atheroma formed ?

While the exact answer is not known, there are some parts of the puzzle that have been unravelled. According to the most popular theory - called the "Reaction to Injury hypothesis" - atherosclerosis is initiated by injury to the inner lining of the artery.

The artery is lined by a single layer of cells called "endothelium", which may be damaged by a variety of insults including high blood pressure, increased concentration of fats in blood, toxins in cigarette smoke and many other factors.

When the endothelium is damaged, it becomes leaky. Fats in the blood can seep through this leaky layer, and irritate the artery wall. Special types of blood cells called platelets and monocytes stick to these areas of injury and release chemical substances.

In response to this irritation by chemicals and fats, the muscle cells in the wall of the arteries move towards the inner lining, and begin to divide and increase in number. They also produce other substances which collect in the inner lining. The monocytes, in addition, imbibe fats from the blood and swell up in size.

The result is the formation of an atheromatous plaque in the inner lining of the artery.

Read more about atherosclerosis:

• Why is an atheromatous plaque dangerous ?
• What are the risk factors for atherosclerosis ?