Angina a symptom of coronary artery disease, is chest pain or discomfort that occurs when the heart muscle is not getting enough blood. Angina may feel like pressure or a squeezing pain in the chest. The pain also may occur in the shoulders, arms, neck, jaw, or back. It may feel like indigestion.

There are two forms of angina—stable or unstable:

• Stable angina happens during physical activity or under mental or emotional stress.
• Unstable angina is chest pain that occurs even while at rest, without apparent reason. This type of angina is a medical emergency.