What is angina pectoris?

Angina pectoris symptoms can be obvious or subtle. It causes chest pain in the form of heaviness, tightness, pressure, aching, burning, numbness, fullness or squeezing. It may also feel like heartburn or indigestion, and any form of angina discomfort may be constant or come and go. The chest discomfort may be accompanied by shortness of breath with minimal exertion (such as walking across a room), nausea, sweating or fatigue.

There are several types of angina, and the signs and symptoms depend on which type you have. The types of angina are stable, unstable, microvascular and variant.

• Stable angina usually follows a pattern, such as discomfort occurring after exercise or when you are under stress. The pain usually goes away after you rest or take angina medicine. If these symptoms occur for at least two months, you may have stable angina. 
• Unstable angina, also referred to as acute coronary syndrome, usually lasts longer than five minutes and may occur with or without physical exertion, and rest or medication may not relieve the pain. (Stable angina could become unstable angina.) The most common cause is atherosclerosis, or reduced blood flow to the heart muscle because the coronary arteries are narrowed by fatty buildup (plaques). In addition to the narrowing , these plaques can rupture, causing blockages leading to cardiac arrest or stroke. Unstable angina is a medical emergency—someone experiencing it should go to the ED.
• Microvascular angina is a sign of ischemic heart diseases that affects the tiny arteries of the heart and can be stable or unstable. The pain associated with this type of angina can be more intense and last longer than other types of anginas and may occur at rest or with exercise. Medication may not relieve this type of chest pain. 
• Variant angina is rare and occurs when the muscles within the arteries of your heart spasm or tighten, interrupting blood flow instead of, or in addition to, plaque buildup. This type of angina usually occurs while you are at rest and often happens between midnight and early morning. Medicine often eases variant angina effectively.