Plaque is a collection of excess cholesterol covered by a scar that is deposited on artery walls. In most cases, this buildup results after years of having high cholesterol. The largest buildups are most likely to cause angina. Small buildups of this substance are thought to be unstable and more likely to rupture, releasing their contents into the bloodstream, possibly causing a blood clot that may trigger a heart attack.
When talking about cholesterol and heart disease, it is helpful to understand plaque. The effect of plaque buildup in the arteries is the main cause of heart disease and heart attacks in people with high cholesterol.
Cholesterol is a major ingredient in the plaque that builds up in the coronary arteries (the blood vessels that supply blood to the heart) and causes heart disease.
Excess cholesterol is deposited on the artery walls as it travels through the bloodstream. Then, special cells in the artery wall gobble up this excess cholesterol, creating a "bump" in the artery wall. This cholesterol-rich "bump" then is covered by a scar that produces a hard coat or shell over the cholesterol and cell mixture. It is this collection of cholesterol covered by a scar that is called plaque. The buildup of plaque is known as atherosclerosis.
The plaque buildup narrows the space in the coronary arteries through which blood can flow, decreasing the supply of oxygen and nutrients to the heart. If not enough oxygen-carrying blood can pass through the narrowed arteries to reach the heart muscle, the heart may respond with a pain called angina. The pain is often felt during exercise, when the heart needs more oxygen. It is typically felt in the chest or sometimes in other places, like the left arm and shoulder. This same inadequate blood supply, however, may cause no symptoms.
This plaque buildup does not occur over days, weeks, or months. Plaque buildup, in most cases, occurs over many years.