What Is

Angina (an-JI-nuh or AN-juh-nuh) is chest pain or discomfort that occurs if an area of your heart muscle doesn't get enough oxygen-rich blood.

Angina may feel like pressure or squeezing in your chest. The pain also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion.

Angina isn't a disease; it's a symptom of an underlying heart problem. Angina usually is a symptom of coronary heart disease (CHD).

CHD is the most common type of heart disease in adults. It occurs if a waxy substance called plaque (plak) builds up on the inner walls of your coronary arteries. These arteries carry oxygen-rich blood to your heart.

Plaque Buildup in an Artery

Figure A shows a normal artery with normal blood flow. The inset image shows a cross-section of a normal artery. Figure B shows an artery with plaque buildup. The inset image shows a cross-section of an artery with plaque buildup.
Figure A shows a normal artery with normal blood flow. The inset image shows a cross-section of a normal artery. Figure B shows an artery with plaque buildup. The inset image shows a cross-section of an artery with plaque buildup.

Plaque narrows and stiffens the coronary arteries. This reduces the flow of oxygen-rich blood to the heart muscle, causing chest pain. Plaque buildup also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow, which can cause a heart attack.

Angina also can be a symptom of coronary microvascular disease (MVD). This is heart disease that affects the heart’s smallest coronary arteries. In coronary MVD, plaque doesn't create blockages in the arteries like it does in CHD.

Studies have shown that coronary MVD is more likely to affect women than men. Coronary MVD also is called cardiac syndrome X and nonobstructive CHD.

Types of Angina

The major types of angina are stable, unstable, variant (Prinzmetal's), and microvascular. Knowing how the types differ is important. This is because they have different symptoms and require different treatments.

Stable Angina

Stable angina is the most common type of angina. It occurs when the heart is working harder than usual. Stable angina has a regular pattern. (“Pattern” refers to how often the angina occurs, how severe it is, and what factors trigger it.)

If you have stable angina, you can learn its pattern and predict when the pain will occur. The pain usually goes away a few minutes after you rest or take your angina medicine.

Stable angina isn't a heart attack, but it suggests that a heart attack is more likely to happen in the future.

Unstable Angina

Unstable angina doesn't follow a pattern. It may occur more often and be more severe than stable angina. Unstable angina also can occur with or without physical exertion, and rest or medicine may not relieve the pain.

Unstable angina is very dangerous and requires emergency treatment. This type of angina is a sign that a heart attack may happen soon.

Variant (Prinzmetal's) Angina

Variant angina is rare. A spasm in a coronary artery causes this type of angina. Variant angina usually occurs while you're at rest, and the pain can be severe. It usually happens between midnight and early morning. Medicine can relieve this type of angina.

Microvascular Angina

Microvascular angina can be more severe and last longer than other types of angina. Medicine may not relieve this type of angina.


Experts believe that nearly 7 million people in the United States suffer from angina. The condition occurs equally among men and women.

Angina can be a sign of CHD, even if initial tests don't point to the disease. However, not all chest pain or discomfort is a sign of CHD.

Other conditions also can cause chest pain, such as:

  • Pulmonary embolism (a blockage in a lung artery)
  • A lung infection
  • Aortic dissection (tearing of a major artery)
  • Aortic stenosis (narrowing of the heart’s aortic valve)
  • Hypertrophic cardiomyopathy (KAR-de-o-mi-OP-ah-thee; heart muscle disease)
  • Pericarditis (inflammation in the tissues that surround the heart)
  • A panic attack

All chest pain should be checked by a doctor.

Other Names

  • Acute coronary syndrome
  • Angina pectoris
  • Chest pain
  • Coronary artery spasms
  • Microvascular angina
  • Prinzmetal's angina
  • Stable or common angina
  • Unstable angina
  • Variant angina


Underlying Causes

Angina usually is a symptom of coronary heart disease (CHD). This means that the underlying causes of angina generally are the same as the underlying causes of CHD.

Research suggests that CHD starts when certain factors damage the inner layers of the coronary arteries. These factors include:

Plaque may begin to build up where the arteries are damaged. When plaque builds up in the arteries, the condition is called atherosclerosis (ath-er-o-skler-O-sis).

Plaque narrows or blocks the arteries, reducing blood flow to the heart muscle. Some plaque is hard and stable and causes the arteries to become narrow and stiff. This can greatly reduce blood flow to the heart and cause angina.

Other plaque is soft and more likely to rupture (break open) and cause blood clots. Blood clots can partially or totally block the coronary arteries and cause angina or a heart attack.

Immediate Causes

Many factors can trigger angina pain, depending on the type of angina you have.

Stable Angina

Physical exertion is the most common trigger of stable angina. Severely narrowed arteries may allow enough blood to reach the heart when the demand for oxygen is low, such as when you're sitting.

However, with physical exertion—like walking up a hill or climbing stairs—the heart works harder and needs more oxygen.

Other triggers of stable angina include:

  • Emotional stress
  • Exposure to very hot or cold temperatures
  • Heavy meals
  • Smoking

Unstable Angina

Blood clots that partially or totally block an artery cause unstable angina.

If plaque in an artery ruptures, blood clots may form. This creates a blockage. A clot may grow large enough to completely block the artery and cause a heart attack. For more information, go to the animation in "What Causes a Heart Attack?"

Blood clots may form, partially dissolve, and later form again. Angina can occur each time a clot blocks an artery.

Variant Angina

A spasm in a coronary artery causes variant angina. The spasm causes the walls of the artery to tighten and narrow. Blood flow to the heart slows or stops. Variant angina can occur in people who have CHD and in those who don’t.

The coronary arteries can spasm as a result of:

  • Exposure to cold
  • Emotional stress
  • Medicines that tighten or narrow blood vessels
  • Smoking
  • Cocaine use

Microvascular Angina

This type of angina may be a symptom of coronary microvascular disease (MVD). Coronary MVD is heart disease that affects the heart’s smallest coronary arteries.

Reduced blood flow in the small coronary arteries may cause microvascular angina. Plaque in the arteries, artery spasms, or damaged or diseased artery walls can reduce blood flow through the small coronary arteries.

Risk Factors

Angina is a symptom of an underlying heart problem. It’s usually a symptom of coronary heart disease (CHD), but it also can be a symptom of coronary microvascular disease (MVD). So, if you’re at risk for CHD or coronary MVD, you’re also at risk for angina.

The major risk factors for CHD and coronary MVD include:

For more detailed information about CHD and coronary MVD risk factors, visit the Diseases and Conditions Index Coronary Heart Disease, Coronary Heart Disease Risk Factors, and Coronary Microvascular Disease articles.

People sometimes think that because men have more heart attacks than women, men also suffer from angina more often. In fact, overall, angina occurs equally among men and women.

Microvascular angina, however, occurs more often in women. About 70 percent of the cases of microvascular angina occur in women around the time of menopause.

Unstable angina occurs more often in older adults. Variant angina is rare; it accounts for only about 2 out of 100 cases of angina. People who have variant angina often are younger than those who have other forms of angina.

Screening and Prevention

You can prevent or lower your risk for angina and heart disease by making lifestyle changes and treating related conditions.

Making Lifestyle Changes

Healthy lifestyle choices can help prevent or delay angina and heart disease. To adopt a healthy lifestyle, you can:

  • Quit smoking and avoid secondhand smoke
  • Avoid angina triggers
  • Follow a healthy diet
  • Be physically active
  • Maintain a healthy weight
  • Learn ways to handle stress and relax
  • Take your medicines as your doctor prescribes

For more information about these lifestyle changes, go to “How Is Angina Treated?” For more information about preventing and controlling heart disease risk factors, visit the Diseases and Conditions Index Coronary Heart Disease, Coronary Heart Disease Risk Factors, and Coronary Microvascular Disease articles.

Treating Related Conditions

You also can help prevent or delay angina and heart disease by treating related conditions, such as high blood cholesterol, high blood pressure, diabetes, and overweight or obesity.

If you have one or more of these conditions, talk with your doctor about how to control them. Follow your treatment plan and take all of your medicines as your doctor prescribes.

Signs, Symptoms, and Complications

Pain and discomfort are the main symptoms of angina. Angina often is described as pressure, squeezing, burning, or tightness in the chest. The pain or discomfort usually starts behind the breastbone.

Pain from angina also can occur in the arms, shoulders, neck, jaw, throat, or back. The pain may feel like indigestion. Some people say that angina pain is hard to describe or that they can't tell exactly where the pain is coming from.

Signs and symptoms such as nausea (feeling sick to your stomach), fatigue (tiredness), shortness of breath, sweating, light-headedness, and weakness also may occur.

Women are more likely to feel discomfort in the neck, jaw, throat, abdomen, or back. Shortness of breath is more common in older people and those who have diabetes. Weakness, dizziness, and confusion can mask the signs and symptoms of angina in elderly people.

Symptoms also vary based on the type of angina you have.

Because angina has so many possible symptoms and causes, all chest pain should be checked by a doctor. Chest pain that lasts longer than a few minutes and isn't relieved by rest or angina medicine may be a sign of a heart attack. Call 9–1–1 right away.

Stable Angina

The pain or discomfort:

  • Occurs when the heart must work harder, usually during physical exertion
  • Doesn't come as a surprise, and episodes of pain tend to be alike
  • Usually lasts a short time (5 minutes or less)
  • Is relieved by rest or medicine
  • May feel like gas or indigestion
  • May feel like chest pain that spreads to the arms, back, or other areas

Unstable Angina

The pain or discomfort:

  • Often occurs at rest, while sleeping at night, or with little physical exertion
  • Comes as a surprise
  • Is more severe and lasts longer than stable angina (as long as 30 minutes)
  • Usually isn’t relieved by rest or medicine
  • May get worse over time
  • May mean that a heart attack will happen soon

Variant Angina

The pain or discomfort:

  • Usually occurs at rest and during the night or early morning hours
  • Tends to be severe
  • Is relieved by medicine

Microvascular Angina

The pain or discomfort:

  • May be more severe and last longer than other types of angina pain
  • May occur with shortness of breath, sleep problems, fatigue, and lack of energy
  • Often is first noticed during routine daily activities and times of mental stress


The most important issues to address when you go to the doctor with chest pain are:

  • What's causing the chest pain
  • Whether you're having or are about to have a heart attack

Angina is a symptom of an underlying heart problem, usually coronary heart disease (CHD). The type of angina pain you have can be a sign of how severe the CHD is and whether it's likely to cause a heart attack.

If you have chest pain, your doctor will want to find out whether it's angina. He or she also will want to know whether the angina is stable or unstable. If it's unstable, you may need emergency medical treatment to try to prevent a heart attack.

To diagnose chest pain as stable or unstable angina, your doctor will do a physical exam, ask about your symptoms, and ask about your risk factors for and your family history of CHD or other heart diseases.

Your doctor also may ask questions about your symptoms, such as:

  • What brings on the pain or discomfort and what relieves it?
  • What does the pain or discomfort feel like (for example, heaviness or tightness)?
  • How often does the pain occur?
  • Where do you feel the pain or discomfort?
  • How severe is the pain or discomfort?
  • How long does the pain or discomfort last?

Diagnostic Tests and Procedures

If your doctor thinks that you have unstable angina or that your angina is related to a serious heart condition, he or she may recommend one or more tests.

EKG (Electrocardiogram)

An EKG is a simple, painless test that detects and records the heart’s electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through the heart.

An EKG can show signs of heart damage due to CHD and signs of a previous or current heart attack. However, some people who have angina have normal EKGs.

Stress Testing

During stress testing, you exercise to make your heart work hard and beat fast while heart tests are done. If you can’t exercise, you may be given medicine to make your heart work hard and beat fast.

When your heart is working hard and beating fast, it needs more blood and oxygen. Plaque-narrowed arteries can't supply enough oxygen-rich blood to meet your heart's needs.

A stress test can show possible signs and symptoms of CHD, such as:

  • Abnormal changes in your heart rate or blood pressure
  • Shortness of breath or chest pain
  • Abnormal changes in your heart rhythm or your heart's electrical activity

As part of some stress tests, pictures are taken of your heart while you exercise and while you rest. These imaging stress tests can show how well blood is flowing in various parts of your heart. They also can show how well your heart pumps blood when it beats.

Chest X Ray

A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels.

A chest x ray can reveal signs of heart failure. It also can show signs of lung disorders and other causes of symptoms not related to CHD. However, a chest x ray alone is not enough to diagnose angina or CHD.

Coronary Angiography and Cardiac Catheterization

Your doctor may recommend coronary angiography (an-jee-OG-ra-fee) if he or she suspects you have CHD. This test uses dye and special x rays to show the inside of your coronary arteries.

To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization (KATH-e-ter-ih-ZA-shun).

A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream.

Special x rays are taken while the dye is flowing through your coronary arteries. The dye lets your doctor study the flow of blood through your heart and blood vessels.

Cardiac catheterization usually is done in a hospital. You're awake during the procedure. It usually causes little or no pain, although you may feel some soreness in the blood vessel where your doctor inserts the catheter.

Computed Tomography Angiography

Computed tomography (to-MOG-rah-fee) angiography (CTA) uses dye and special x rays to show blood flow through the coronary arteries. This test is less invasive than coronary angiography with cardiac catheterization.

For CTA, a needle connected to an intravenous (IV) line is put into a vein in your hand or arm. Dye is injected through the IV line during the scan. You may have a warm feeling when this happens. The dye highlights your blood vessels on the CT scan pictures.

Sticky patches called electrodes are put on your chest. The patches are attached to an EKG machine to record your heart's electrical activity during the scan.

The CT scanner is a large machine that has a hollow, circular tube in the middle. You lie on your back on a sliding table. The table slowly slides into the opening of the machine.

Inside the scanner, an x-ray tube moves around your body to take pictures of different parts of your heart. A computer puts the pictures together to make a three-dimensional (3D) picture of the whole heart.

Blood Tests

Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may show that you have risk factors for CHD.

Your doctor may recommend a blood test to check the level of a protein called C-reactive protein (CRP) in your blood. Some studies suggest that high levels of CRP in the blood may increase the risk for CHD and heart attack.

Your doctor also may recommend a blood test to check for low levels of hemoglobin (HEE-muh-glow-bin) in your blood. Hemoglobin is an iron-rich protein in red blood cells. It helps the blood cells carry oxygen from the lungs to all parts of your body. If your hemoglobin level is low, you may have a condition called anemia (uh-NEE-me-uh).


Treatments for angina include lifestyle changes, medicines, medical procedures, cardiac rehabilitation (rehab), and other therapies. The main goals of treatment are to:

  • Reduce pain and discomfort and how often it occurs
  • Prevent or lower your risk for heart attack and death by treating your underlying heart condition

Lifestyle changes and medicines may be the only treatments needed if your symptoms are mild and aren't getting worse. If lifestyle changes and medicines don't control angina, you may need medical procedures or cardiac rehab.

Unstable angina is an emergency condition that requires treatment in a hospital.

Lifestyle Changes

Making lifestyle changes can help prevent episodes of angina. You can:

  • Slow down or take rest breaks if physical exertion triggers angina.
  • Avoid large meals and rich foods that leave you feeling stuffed if heavy meals trigger angina.
  • Try to avoid situations that make you upset or stressed if emotional stress triggers angina. Learn ways to handle stress that can't be avoided.

You also can make lifestyle changes that help lower your risk for coronary heart disease. One of the most important changes is to quit smoking. Smoking can damage and tighten blood vessels and raise your risk for CHD. Talk with your doctor about programs and products that can help you quit. Also, try to avoid secondhand smoke.

If you have trouble quitting smoking on your own, consider joining a support group. Many hospitals, workplaces, and community groups offer classes to help people quit smoking.

For more information about how to quit smoking, go to the Diseases and Conditions Index (DCI) Smoking and Your Heart article and the National Heart, Lung, and Blood Institute’s (NHLBI’s) "Your Guide to a Healthy Heart."

Following a healthy diet is another important lifestyle change. A healthy diet can prevent or reduce high blood pressure and high blood cholesterol and help you maintain a healthy weight.

A healthy diet includes a variety of fruits and vegetables (including beans and peas). It also includes whole grains, lean meats, poultry without skin, seafood, and fat-free or low-fat milk and dairy products. A healthy diet also is low in sodium (salt), added sugars, solid fats, and refined grains.

For more information about following a healthy diet, go to the NHLBI’s “Your Guide to Lowering Your Blood Pressure With DASH” and the U.S. Department of Agriculture’s Web site. Both resources provide general information about healthy eating.

Other important lifestyle changes include:

  • Being physically active. Check with your doctor to find out how much and what kinds of activity are safe for you. For more information, go to the DCI Physical Activity and Your Heart article.
  • Maintaining a healthy weight. If you’re overweight or obese, work with your doctor to create a reasonable weight-loss plan. Controlling your weight helps you control CHD risk factors.
  • Taking all medicines as your doctor prescribes, especially if you have diabetes.


Nitrates are the medicines most commonly used to treat angina. They relax and widen blood vessels. This allows more blood to flow to the heart, while reducing the heart’s workload.

Nitroglycerin (NI-tro-GLIS-er-in) is the most commonly used nitrate for angina. Nitroglycerin that dissolves under your tongue or between your cheek and gum is used to relieve angina episodes.

Nitroglycerin pills and skin patches are used to prevent angina episodes. However, pills and skin patches act too slowly to relieve pain during an angina attack.

Other medicines also are used to treat angina, such as beta blockers, calcium channel blockers, ACE inhibitors, oral antiplatelet medicines, or anticoagulants (blood thinners). These medicines can help:

  • Lower blood pressure and cholesterol levels
  • Slow the heart rate
  • Relax blood vessels
  • Reduce strain on the heart
  • Prevent blood clots from forming

People who have stable angina may be advised to get annual flu shots.

Medical Procedures

If lifestyle changes and medicines don't control angina, you may need a medical procedure to treat the underlying heart disease. Both angioplasty (AN-jee-oh-plas-tee) and coronary artery bypass grafting (CABG) are commonly used to treat heart disease.

Angioplasty opens blocked or narrowed coronary arteries. During angioplasty, a thin tube with a balloon or other device on the end is threaded through a blood vessel to the narrowed or blocked coronary artery.

Once in place, the balloon is inflated to push the plaque outward against the wall of the artery. This widens the artery and restores blood flow.

Angioplasty can improve blood flow to your heart and relieve chest pain. A small mesh tube called a stent usually is placed in the artery to help keep it open after the procedure.

During CABG, healthy arteries or veins taken from other areas in your body are used to bypass (that is, go around) your narrowed coronary arteries. Bypass surgery can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack.

You will work with your doctor to decide which treatment is better for you.

Cardiac Rehabilitation

Your doctor may recommend cardiac rehab for angina or after angioplasty, CABG, or a heart attack. Cardiac rehab is a medically supervised program that can help improve the health and well-being of people who have heart problems.

The cardiac rehab team may include doctors, nurses, exercise specialists, physical and occupational therapists, dietitians or nutritionists, and psychologists or other mental health specialists.

Rehab has two parts:

  • Exercise training. This part helps you learn how to exercise safely, strengthen your muscles, and improve your stamina. Your exercise plan will be based on your personal abilities, needs, and interests.
  • Education, counseling, and training. This part of rehab helps you understand your heart condition and find ways to reduce your risk for future heart problems. The rehab team will help you learn how to adjust to a new lifestyle and deal with your fears about the future.

For more information about cardiac rehab, go to the DCI Cardiac Rehabilitation article.

Enhanced External Counterpulsation Therapy

Enhanced external counterpulsation (EECP) therapy is helpful for some people who have angina. Large cuffs, similar to blood pressure cuffs, are put on your legs. The cuffs are inflated and deflated in sync with your heartbeat.

EECP therapy improves the flow of oxygen-rich blood to your heart muscle and helps relieve angina. You typically get 35 1-hour treatments over 7 weeks.

Living With

Angina isn't a heart attack, but it does increase your risk of having a heart attack. The risk is even higher if you have unstable angina. For these reasons, it's important that you know:

  • The usual pattern of your angina, if you have it regularly.
  • What medicines you take (keep a list) and how to take them. Make sure your medicines are readily available.
  • How to control your angina.
  • The limits of your physical activity.
  • How and when to seek medical attention.

Know the Pattern of Your Angina

Stable angina usually occurs in a pattern. You should know:

  • What causes the pain to occur
  • What the pain feels like
  • How long the pain usually lasts
  • Whether rest or medicine relieves the pain

After several episodes, you’ll learn the pattern of your angina. You’ll want to pay attention to whether the pattern changes. Pattern changes may include angina that occurs more often, lasts longer, is more severe, occurs without physical exertion, or doesn't go away with rest or medicines.

These changes may be a sign that your symptoms are getting worse or becoming unstable. You should seek medical help. Unstable angina suggests that you're at high risk for a heart attack very soon.

Know Your Medicines

You should know what medicines you're taking, the purpose of each, how and when to take them, and possible side effects. Know exactly when and how to take fast-acting nitroglycerin or other nitrates to relieve chest pain.

Correctly storing your angina medicines and knowing when to replace them also is important. Your doctor can advise you about this.

If you have side effects from your medicines, let your doctor know. You should never stop taking your medicines without your doctor's approval.

Talk with your doctor if you have any questions or concerns about taking your angina medicines. Tell him or her about any other medicines you’re taking. Some medicines can cause serious problems if they're taken with nitrates or other angina medicines.

Know How To Control Your Angina

After several angina episodes, you’ll know the level of activity, stress, and other factors that trigger your angina. By knowing this, you can take steps to prevent or lessen the severity of episodes.

Physical Exertion

Know what level of physical exertion triggers your angina and try to stop and rest before chest pain starts. For example, if walking up a flight of stairs leads to chest pain, stop halfway and rest before continuing.

If chest pain occurs during physical exertion, stop and rest or take your angina medicine. The pain should go away in a few minutes. If the pain doesn't go away or lasts longer than usual, call 9–1–1 for emergency care.

Emotional Stress

Anger, arguing, and worrying are examples of emotional stress that can trigger angina. Try to avoid or limit situations that cause these emotions.

Exercise and relaxation can help relieve stress. Alcohol and drug use play a part in causing stress and don't relieve it. If stress is a problem for you, talk with your doctor about getting help for it.

Eating Large Meals

If large meals lead to chest pain, eat smaller meals. Also, avoid eating rich foods.

Know the Limits of Your Physical Activity

Most people who have stable angina can continue their normal activities. This includes work, hobbies, and sexual relations. However, if you do very strenuous activities or have a stressful job, talk with your doctor.

Know How and When To Seek Medical Attention

Angina increases your risk for a heart attack. It’s important that you and your family know how and when to seek medical attention.

Talk with your doctor about making an emergency action plan. The plan should include making sure you and your family members know:

  • The signs and symptoms of a heart attack
  • How to use aspirin and nitroglycerin when needed
  • How to access emergency medical services in your community
  • The location of the nearest hospital that offers 24-hour emergency heart care

Discuss your emergency plan with your family members. Take action quickly if your chest pain becomes severe, lasts longer than a few minutes, or isn't relieved by rest or medicine.

Sometimes it’s hard to tell the difference between unstable angina and a heart attack. Both are emergencies, so you should call 9–1–1 right away.

Participate in NHLBI Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) leads or sponsors many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.

Can chelation therapy prevent complications of ischemic heart disease in people with diabetes?

This study is following up on a prior study showing that the risk of complications from ischemic heart disease, including unstable angina, was lowered by chelation and high-dose vitamin treatments given to people with diabetes who had a prior heart attack. To participate in this study, you must be at least 50 years old, have a history of diabetes, and have had a heart attack. This study is located in Miami, Florida.
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