Atherosclerosis is hardening of a blood vessel from a buildup of plaque. Plaque is made of fatty deposits, cholesterol, and calcium. Plaque buildup causes the artery to narrow and harden. Plaque buildup can slow and even stop blood flow. This means the tissue supplied by the artery is cut off from its blood supply. This often leads to pain or decreased function. This condition can cause several life threating health problems. Depending on the location of the blockage, it can cause:
Coronary heart disease —Loss of blood to areas of the heart
Stroke —Loss of blood to areas of the brain
Peripheral vascular disease —Loss of blood to the extremities.
A hardened artery is more likely to be damaged. Repeated damage to the inner wall of an artery causes blood clots to form. The clots are called thrombi. They can lead to a further decrease in blood flow. A thrombus sometimes becomes so large that it completely closes off the artery. It could also break into clumps, called emboli. These clumps travel through the bloodstream and lodge in smaller arteries, blocking them off. The one tissue supplied by the artery receives no oxygen. It quickly dies. When this occurs in the heart, it is called a heart attack. In the brain, it is called a stroke. Long-term atherosclerosis can also cause arteries to weaken. They may bulge under pressure. This bulge is called an aneurysm. If untreated, they can rupture and bleed