The three types of angina are stable, unstable, and variant (Prinzmetal's). It is very important to know the differences among the types.

Stable angina

Stable angina is the most common type. It occurs when the heart is working harder than usual.

• There is a regular pattern to stable angina. After several episodes, you learn to recognize the pattern and can predict when it will occur.
• The pain usually goes away in a few minutes after you rest or take your angina medicine.
• Stable angina is not a heart attack but makes it more likely that you will have a heart attack in the future.

Unstable angina

Unstable angina is a very dangerous condition that requires emergency treatment. It is a sign that a heart attack could occur soon. Unlike stable angina, it does not follow a pattern. It can occur without physical exertion and is not relieved by rest or medicine.

Variant angina

Variant angina is rare. It usually occurs at rest. The pain can be severe and usually occurs between midnight and early morning. It is relieved by medicine.

Not all chest pain or discomfort is angina. Chest pain or discomfort can be caused by a heart attack, lung problems (such as an infection or a blood clot), heartburn, or a panic attack. However, all chest pain should be checked by a doctor.