Unstable angina is a dangerous condition that requires emergency treatment. It is a sign that a heart attack could occur soon. Unlike stable angina, it does not follow a pattern. It can occur without physical exertion and is not relieved by rest or medicine.
Variant angina is rare; it usually occurs at rest. The pain can be severe and usually occurs between midnight and early morning. This pain can usually be relieved by medicine.
Angina is caused by a temporary lack of oxygen-rich blood to the heart muscle. This decrease in blood flow can happen for a number of reasons and will vary, based on the type. Most commonly, the cause of angina is coronary artery disease (CAD), or what most people refer to as just heart disease. Sometimes, other types of heart disease (such as aortic stenosis) or uncontrolled high blood pressure (hypertension) can cause angina.
For a lot of people (especially those with stable angina), symptoms are triggered by:
- Physical exertion, such as exercise, hurrying, or sexual activity
- Emotion (stress, anger, frustration, fright)
- Exposure to extreme hot or cold temperatures
- Heavy meals
Unstable and variant angina are usually not associated with triggers.
Specific angina risk factors include:
- Coronary artery disease, also known as coronary heart disease
- Other heart diseases, such as aortic stenosis or hypertrophic cardiomyopathy
- Previous heart attack
Stable and unstable angina occurs more often in older adults. People with variant angina are often younger than those with other forms of the condition.