Atherosclerosis is nothing but a condition in which, the inner walls of the arteries narrow, due to the formation of plaques, which blocks the blood flow to the various parts of the body. It's causes are not really known, but it can appear in people in a very young age, possibly in their childhood or in the adolescent age.
The plaque formation can happen anywhere in the body and based on where it happens, different kind of problems occur. Most dangerous are the conditions in which the wall narrows in the arteries carrying blood to the heart and brain.
When it happens on the arteries carrying blood to the heart, heart attacks and strokes might happen. If it happens on the arteries carrying blood to the body parts like hands or legs, then it might lead to the numbness of the body parts and in some cases even infections.
These plaque formations mostly occur in people who have relatively higher levels of cholesterol. These plaques are made of dead tissue, blood platelets, lipoproteins, decaying muscle cells and sometimes even calcium.
In the US alone, a lot of deaths have occurred due to Atherosclerosis, since it's symptoms and signs are not really known to the people till they get some major heart problems or strokes.
As people get older, the size and number of the plaques increase causing more problems for the affected person.