What is Atherosclerosis?
"Hardening of the Arteries"
Atherosclerosis literally means "hardening of the arteries". It is a build up of cholesterol and other fat substances within the walls of the arteries. Atherosclerosis is a progressive disease and can develop in any artery in the body. It is a common disorder of the arteries.
Atherosclerosis is the major form of heart disease in Western countries. Over one half of all deaths in the US are a direct or indirect result of atherosclerosis. Atherosclerosis is triggered by excess amounts of unstable particles known as oxygen-free radicals, which bind with and alter other molecules, a process called oxidation. The particles are usually released as part of normal bodily processes, but environmental toxins, such as viruses or smoking, can hinder the body from releasing them and produce excess amounts.
In atherosclerosis, fatty deposits called plaque, build up on the inner wall of the coronary arteries. These fatty deposits usually develop over many years. Plaque is composed of a porridge-like accumulation of cholesterol and their compounds within a fibrous coat. Cholesterol buildup is very hazardous. After it builds up, the injury to the arteries signal the immune system to release white blood cells (particularly those called macrophages) at the site. This initiates a process called the inflammatory response. Macrophages literally "eat" the oxidized cholesterol leaving behind foamy cells that attach to the artery's smooth muscle cells. The foamy cells then buildup within the artery. After the immune system senses the foamy cells, it releases other factors called cytokines, which attract more white blood cells and perpetuate the whole cycle. This cycle usually repeats itself forming atherosclerotic lesions.
Atherosclerosis affects medium and large sized arteries in the body. It most frequently affects the aorta (the largest blood vessel in the body), the coronary arteries, the cerebral arteries (which supply the brain) and sometimes arteries in the legs and abdomen. The involvement of the arteries is usually located at places where the artery branches into two.
The fact that atherosclerosis affects the aorta, coronary arteries and cerebral arteries is very important. If the blood supply to the heart muscle is reduced, a heart attack can occur. If the blood supply to the brain is cut off, a stroke can occur. And if the blood supply to the arms and legs is reduced, gangrene can result.
Symptoms of atherosclerosis vary between individuals. They include shortness of breath and tightening pain in the chest. However, usually no symptoms are visible until a complication occurs.