Angina is chest pain that emanates from the nerves of the heart when the heart's demand for oxygen outpaces the supply provided by blood. It is caused by conditions in which either the oxygen supply is limited or the demand for oxygen is increased. The variable in angina grading is the level of activity, with greater activity requiring more oxygen by the heart. There are many causes of angina attacks, some more serious than others.
Coronary Artery Disease
The chest pain of stable angina tends to come and go predictably. Coronary artery disease narrows the arteries, making it more difficult for the heart to get blood when demand increases. This triggers angina when there is physical exertion such as running, climbing stairs or walking. It can also be brought about by very hot or cold temperatures, stress and emotional upset, smoking and heavy meals.
Atherosclerosis
Unstable angina comes and goes unpredictably and likely occurs at rest. Like with stable angina, it is associated with narrowed arteries, typically from atherosclerosis, the buildup of cholesterol in the blood vessels. Unstable angina is a medical emergency and should be evaluated by medical professionals. The American Heart Associate says unstable angina attacks can be caused by rupture of a cholesterol plaque, formation of a blood clot or severe anemia.
Coronary Blood Vessel Spasms
Prinzmetal's or variant angina, is caused by spasm of the coronary blood vessels. The spasm causes narrowing of the blood vessels and restriction of blood flow. It may also be associated with coronary artery disease, but not always. Factors that trigger variant angina attacks include smoking, cocaine use, medications that narrow blood vessels, exposure to extreme temperatures and stress, according to MedlinePlus.
