Angina is chest pain usually felt when there is not enough blood flow to the heart, thus depriving the heart of its oxygen requirements. It may feel like pressure or heaviness in your chest, as well as manifest itself like indigestion. The pain may radiate to your arms, neck or back.
Angina is mostly indicative of coronary artery disease(CAD), usually the result of plaque buildup in the vital arteries supplying oxygen to the heart. There are two types of angina, stable and unstable. In the stable type, usually, the heart works more than necessary to cope with the diminishing oxygen supply. Medicine and rest is the usual therapy. In unstable angina, which is the most dangerous kind, there is no specific pattern and does not respond to medicine or rest. I hope this helps.