<p>Angina is <a href="https://medlineplus.gov/chestpain.html">chest pain</a> or discomfort you feel when there is not enough blood flow to your heart muscle. Your heart muscle needs the oxygen that the blood carries. Angina may feel like pressure or a squeezing pain in your chest. It may feel like indigestion. You may also feel pain in your shoulders, arms, neck, jaw, or back. </p> <p>Angina is a symptom of <a href="https://medlineplus.gov/coronaryarterydisease.html">coronary artery disease</a> (CAD), the most common <a href="https://medlineplus.gov/heartdiseases.html">heart disease</a>. CAD happens when a sticky substance called plaque builds up in the arteries that supply blood to the heart, reducing blood flow.</p> <p>There are three types of angina:</p> <ul> <li>Stable angina is the most common type. It happens when the heart is working harder than usual. Stable angina has a regular pattern. Rest and medicines usually help.</li> <li>Unstable angina is the most dangerous. It does not follow a pattern and can happen without physical exertion. It does not go away with rest or medicine. It is a sign that you could have a heart attack soon.</li> <li>Variant angina is rare. It happens when you are resting. Medicines can help.</li> </ul> <p>Not all chest pain or discomfort is angina. If you have chest pain, you should see your health care provider.</p> <p class="">NIH: National Heart, Lung, and Blood Institute</p>