What does “unstable” angina mean?
“Unstable” angina is a form of angina that is much more serious than stable angina. Unstable angina occurs when a person is resting, asleep, or undergoes physical exertion. Severe discomfort may come on suddenly in someone who has never had angina before. Attacks may intensify or happen more often. Unstable angina is caused by blood clots that form around damaged plaque (fatty deposit) within a coronary artery. Sometimes the clot washes away after the damage has healed.