Some people never experience chest pain even when the heart is clearly suffering from a lack of oxygen. However, these people often experience other symptoms instead of chest pain. For example, you may have difficulty breathing or you may feel like you have heartburn or indigestion, but in fact your heart is being deprived of oxygen. When these symptoms are caused by coronary artery disease (CAD), your doctor will interpret them the same as though you have angina. For this reason, these types of symptoms are called "anginal equivalents." Because some symptoms of CAD can be very different from actual chest pain, you must tell your doctor about all the symptoms you have been experiencing.