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The most common cause of
angina is coronary artery disease. A less common cause of angina is spasm of the
coronary arteries. Coronary arteries supply oxygenated blood to the heart
muscle. Coronary artery disease develops as cholesterol is deposited in the
artery wall, causing the formation of a hard, thick substance called cholesterol
plaque. The accumulation of cholesterol plaque over time causes narrowing of the
coronary arteries, a process called arteriosclerosis. Arteriosclerosis can be
accelerated by smoking, high blood pressure, elevated cholesterol, and diabetes.
When coronary arteries become narrowed by more than 50% to 70%, they can no
longer meet the increased blood oxygen demand by the heart muscle during
exercise or stress. Lack of oxygen to the heart muscle causes chest pain
(angina). For further information on cholesterol, please read the Cholesterol
article.
The walls of the arteries are
surrounded by muscle fibers. Rapid contraction of these muscle fibers causes a
sudden narrowing (spasm) of the arteries. A spasm of the coronary arteries
reduces blood to the heart muscle and causes angina. Angina as a result of a
coronary artery spasm is called "variant" angina or Prinzmetal angina.
Prinzmetal angina typically occurs at rest, usually in the early morning hours.
Spasms can occur in normal coronary arteries as well as in those already
narrowed by arteriosclerosis.
Risks
factors
- Smoking
- Hypertension - high
blood pressure.
- High Cholesterol
- Diabetes
- Obesity or being
overweight
- Lack of physical
activity
- Alcohol in
quantity
- Family
history
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