Johns Hopkins Health Alerts | Heart Health | The Difference Between Stable Angina and Unstable Angina

Your chest pain may be a symptom of stable angina – or something more serious. Johns Hopkins doctors explain the important difference.

Chest pains can be frightening, no matter what causes them. But if stable angina is the cause, you can take steps to prevent the chest pain or relieve the pain if it occurs. Angina is a warning sign that your heart needs more oxygen. In technical terms, the symptoms of angina are the result of myocardial ischemia (a shortage of blood and oxygen to the heart muscle due to the partial blockage of a coronary artery by the buildup of plaque). Stable angina occurs most often during physical activity, when the heart requires more oxygen than it does at rest but cannot get a sufficient supply because of the narrowing of one or more of the coronary arteries. Angina symptoms usually occur only when an artery is narrowed by 60–70%.

Recognizing the symptoms of angina

When people feel the discomfort of stable angina, they’re often worried that they’re having a heart attack. However, an episode of angina is not a heart attack; the chest pain subsides quickly with rest or nitroglycerin, and there is usually no lasting damage to the heart muscle. If you have stable angina, the most common symptom is a feeling of pressure beneath the breastbone. Some people experience other symptoms, such as sensations of tightness, squeezing, burning, aching, heaviness, or choking in the chest area. Angina can also produce pain in the left shoulder that radiates up to the neck and jaw, or pain in the inner part of the left arm that may travel down to the fingers. The intensity of the discomfort usually increases steadily, reaches a plateau, and gradually diminishes with rest—all within a few minutes. The pain, although uncomfortable, is rarely sharp.

Unstable angina, sometimes called crescendo angina, is a condition midway in severity between stable angina and a heart attack. If you have unstable angina, an inadequate supply of oxygen is reaching your heart, most likely because a blood clot or spasm of the coronary artery has narrowed—but not completely blocked—the artery. Like a heart attack, unstable angina is a medical emergency. In fact, it is a sign that a heart attack could occur soon. Unstable angina has three major features that distinguish it from stable angina:

• The angina is unexpected and can occur at rest.
• The angina is more severe and usually lasts for longer than 20 minutes.
• The angina is not relieved by rest or medication.

Call 911 immediately if you think your chest pains are more than just stable angina. You’ll be taken to the hospital, where doctors can evaluate your chest pain. If unstable angina is diagnosed, you will likely need to stay in the hospital for about 2–5 days to receive treatment to prevent a heart attack.

Johns Hopkins Health Alerts | Heart Health | The Difference Between Stable Angina and Unstable Angina