• Stable angina. This is the most common. Physical activity or stress can trigger it. It usually lasts a few minutes, and it goes away when you rest. It isn't a heart attack, but it can be a sign that you're more likely to have one. Tell your doctor if this happens to you.

Stable angina follows a pattern that has been consistent for at least 2 months. That means the following factors have not changed:

• How long your angina events last;

• How often your angina events occur;

• How well angina responds to rest or medicines;

• The causes or triggers of your angina.

If you have stable angina, you can learn its pattern and predict when an event will occur, such as during physical exertion or mental stress. The pain typically goes away a few minutes after you rest or take your angina medicine. If the condition causing your angina gets worse, stable angina can become unstable angina.

• Unstable angina. You can have this while you're at rest or not very active. The pain can be strong and long-lasting, and it may come back again and again. It can be a signal that you're about to have a heart attack, so see a doctor right away. This is a medical emergency! Call 9-1-1.

 Unstable angina does not follow a pattern. It may be new or occur more often and be more severe than stable angina. Unstable angina can also occur with or without physical exertion. Rest or medicine may not relieve the pain.

Unstable angina is a medical emergency since it can progress to a heart attack. Medical attention may be needed right away to restore blood flow to the heart muscle.

Unstable Angina Signs:

• Occurs even at rest;

• Is a change in your usual pattern of angina;

• Is unexpected;

• Is usually more severe and lasts longer than stable angina, maybe 30 minutes or longer;

• May not disappear with rest or use of angina medication;

• Might signal a heart attack.

• Variant angina or Prinzmetal's angina. It's caused by a spasm in your heart's arteries that temporarily reduces blood flow. It typically happens when you're resting. It is often severe and may be relieved by angina medication. This type is rare. It might happen at night while you're sleeping or resting. Your heart arteries suddenly tighten or narrow. It can cause a lot of pain, and you should get it treated. It typically happens between midnight and early morning and in a pattern. Medicine can ease symptoms of variant angina.

 •          Microvascular angina is a sign of ischemic heart disease affecting the tiny arteries of the heart. Microvascular angina events can be stable or unstable. They can be more painful and last longer than other types of angina, and symptoms can occur during exercise or at rest. Medicine may not relieve symptoms of this type of angina. With this type, you have chest pain but no coronary artery blockage. Instead, it happens because your smallest coronary arteries aren’t working the way they should, so your heart doesn’t get the blood it needs. The chest pain usually lasts more than 10 minutes. This type is more common in women.