Angina happens when there is not enough blood flow to the heart muscle. This low blood flow is often a result of coronary artery disease. Coronary artery disease happens when fatty deposits called plaque (say "plak") build up inside your coronary arteries. This plaque may limit the amount of blood to your heart muscle.

Most people feel angina symptoms in their chest. The most common symptom is chest pain or pressure, or a strange feeling in the chest. But you might feel symptoms in other parts of your body. Some people feel pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or in one or both shoulders or arms.

Other symptoms of angina include shortness of breath, nausea or vomiting, lightheadedness or sudden weakness, or a fast or irregular heartbeat.

Angina can be stable or unstable. Stable angina means that you can usually predict when your symptoms will happen. You probably know what things cause your angina. Angina may be caused by a few things, including activity, stress, smoking, and being exposed to cold. Stable angina can be relieved by rest or nitroglycerin. Unstable angina means that your symptoms have changed and are not following your typical pattern of stable angina. Unstable angina may mean that you are having a heart attack.

If you have angina, pay attention to your symptoms, know what is typical for you, learn how to control it, and understand when you need to get treatment.