Angina is a type of chest pain that occurs when there is not enough
blood flow to the heart. This is often a result of narrowing of the blood
vessels that supply blood to the heart.
Stable angina occurs at fairly predictable times, usually with
activity or exertion. It is relieved by rest and may continue without much
change for years. Stable angina develops after a predictable amount of exertion
or emotion and usually lasts 1 to 5 minutes.
A change in the usual pattern of stable angina means that the blood
flow has become more impaired (called unstable angina). It is a warning sign
that a heart attack may soon occur.
