Three types of angina

	Stable angina
	Unstable angina
	Variant angina (coronary spasm)

Stable angina: A type of angina brought on by an imbalance between the heart’s need for oxygen-rich blood and the amount available. It is "stable," which means the same activities bring it on; it feels the same way each time; and is relieved by rest and/or oral medications. Stable angina is a warning sign of heart disease and should be evaluated by a doctor. If the pattern of angina changes, it may progress to unstable angina.

Unstable angina: This type of angina is considered an acute coronary syndrome. It may be a new symptom or a change from stable angina. The angina may occur more frequently, occur more easily at rest, feel more severe, or last longer. Although this angina can often be relieved with oral medications, it is unstable and may progress to a heart attack. Usually more intense medical treatment or a procedure is required. Unstable angina is an acute coronary syndrome and should be treated as an emergency.

Variant angina: A coronary artery can go into spasm, disrupting blood flow to the heart muscle (ischemia). It can occur in people without significant coronary artery disease. However, two thirds of people with variant angina have severe disease in at least one vessel, and the spasm occurs at the site of blockage. This type of angina is not common and almost always occurs when a person is at rest - during sleep. You are at increased risk for coronary spasm if you have: underlying coronary artery disease, smoke, or use stimulants or illicit drugs (such as cocaine). If a coronary artery spasm is severe and occurs for a long period of time, a heart attack can occur.