Coronary artery disease

At a glance

  • CAD develops if the blood vessels that supply the heart with oxygen become too narrow.
  • This can cause symptoms such as a tight chest, shortness of breath and nausea.
  • Medication can relieve the symptoms and lower the risk of complications.
  • When someone has a heart attack, at least one of these vessels becomes blocked. As a result, the heart doesn't get enough oxygen.
  • If you think someone is having a heart attack, it's important to act quickly in order to avoid or limit lasting damage.
  • Even if you're in any doubt, you should still call the emergency services (112 in Germany and many other countries, 911 in the U.S.).


Photo of a woman gardening

Coronary artery disease (CAD) develops if the large blood vessels that supply the heart with oxygen (the coronary arteries) become too narrow. This happens if deposits build up in the arteries over time. CAD is also known as coronary heart disease (CHD).

CAD can be acute or chronic. Acute CAD leads to a because one or more coronary arteries are blocked by a blood clot. As a result, part of the heart doesn't get any oxygen. It is important to act quickly because otherwise that part might die. Heart attacks are often treated with a (a thin, flexible tube) to quickly open the blocked artery again.

In chronic ("stable") CAD, a coronary artery is permanently too narrow. As a result, less blood flows to the heart muscle. The heart is then no longer able to beat more strongly during physical activity because it doesn't have enough oxygen. That can cause symptoms such as shortness of breath and a tight feeling in the chest. The symptoms go away again after resting for a few minutes, or after taking medicine.

If you have had a or if you have chronic CAD, it can be a good idea to take medication over the long term in order to protect the blood vessels and prevent blood clots. That lowers the risk of other medical problems developing.


Possible symptoms of CAD include chest pain. Some people describe the pain as dull, pressing, constricting, or burning. Others may feel more like they have a large knot in their chest or throat, or as if they have a heavy weight on their chest. These kinds of symptoms, called angina (or angina pectoris), can make you feel anxious or scared.

The pain often spreads into the arms, neck, back, upper belly, or jaw. This may be accompanied by shortness of breath, nausea, dizziness and general weakness, sweating, or cold sweats.

Chest tightness is a less common CAD symptom in women, older people, and people with diabetes or heart failure. They are then more likely to have symptoms such as shortness of breath, upper abdominal pain, and palpitations. Heart attacks can even go unnoticed (silent ) in people with diabetes-related nerve damage.

For people who are experiencing CAD symptoms for the first time, it's difficult to tell whether the symptoms are caused by stable CAD following exertion, or by a . So it's important to know the possible signs of a and know what to do in an emergency.

Illustration: Typical areas of pain during a heart attack or angina pectoris – as described in the article


CAD is caused by arteriosclerosis (hardening of the arteries). Arteries are blood vessels that transport blood to the tissues and organs of the body. Arteriosclerosis starts with small inflammations and damage on and in the wall of the arteries. Immune system cells, fats and other substances collect there. These deposits are called plaques. They can get bigger over time and then block the flow of blood in the artery.

In CAD, at least one coronary artery is affected by arteriosclerosis. The coronary arteries are marked red in the following illustration. The blue vessels are the coronary veins, which take the blood away once the oxygen in it has been used up.

Illustration: Heart with coronary arteries

Arteriosclerosis can have various effects:

  • In chronic CAD, one of the coronary arteries is so narrow that not enough oxygen gets to the heart during physical activity. Then the heart can no longer beat strongly enough to go up the stairs, for instance. That can cause certain symptoms that get better again after resting. These typically occur if the artery is at least 70% narrower than usual. Chronic CAD is also referred to as stable CAD because the symptoms often don't get worse over a long period of time, especially if kept under control with good treatment.
  • In acute CAD, one of the arteries is completely or almost completely blocked. That causes a because too little blood reaches the heart to keep the muscle cells alive. That can happen if a deposit in the wall of the blood vessel suddenly breaks open, and a blood clot forms there and blocks the vessel. If the blockage isn't treated quickly, the part of the heart muscle that doesn't get enough blood dies.

Risk factors

The risk of coronary artery disease increases with age. Other risk factors for CAD include smoking, being very overweight, high cholesterol, high blood pressure, and diabetes.

The risk is particularly high if a person has a number of risk factors at the same time.


CAD is a common chronic disease. Older people are more likely to have it: Around 2% of 40 to 49-year-olds have CAD, compared to 22% of 70 to 79-year-olds. It is somewhat more common in men than in women.


Deposits in the coronary arteries usually develop over many years.

In chronic (stable) CAD, the symptoms are triggered by physical or emotional strain. The point at which the symptoms start is sometimes called the physical activity threshold. The symptoms go away quickly if you rest or take the right medicine.

The severity of the symptoms depends on various things, including how much blood is still reaching the heart muscle. There are four levels of severity:

Table: Severity of angina
Class Severity of symptoms
Class 1 Chest pain only after unusual or prolonged physical activity, but not during basic everyday activities like walking or climbing stairs.
Class 2 Chest pain during more intense activities like walking quickly, walking uphill and climbing stairs after eating, when it's cold or when also under emotional stress.
Class 3 Chest pain even during low-intensity physical activities like walking or getting dressed.
Class 4 Chest pain when at rest or during the gentlest physical activities. This is then referred to as "unstable angina."

Chronic CAD can take different courses. According to current knowledge, good long-term treatment can even make angina symptoms disappear again.

Chronic CAD is often stable for a long time. But it can sometimes also progress and cause a . So it's important for people with CAD to know the signs of a . These include:

  • Symptoms that suddenly get worse without physical or emotional strain (at rest)
  • Symptoms that appear sooner, last longer or are more severe than usual
  • Symptoms that don't get better even after taking emergency medication such as nitrates

It is not always easy to tell the difference between temporary symptoms and a . If in doubt, you should never wait. Call the emergency services straight away (112 in Germany and many other countries, 911 in the U.S.).


CAD can also lead to other health problems. The main ones are (further) heart attacks, an irregular heartbeat like atrial fibrillation, and heart failure (cardiac insufficiency).

Some people who have CAD may develop depression too, especially after a .


Symptoms in the chest area can be caused by many different things, including problems affecting the muscles or bones in the rib cage. Diseases of the lungs, food pipe or the airways can also cause chest pains, as can emotional strain and mental illnesses. Other cardiovascular diseases such as heart muscle inflammations (myocarditis) and irregular heartbeats can also cause similar symptoms.

To get an idea of whether it's CAD, the doctor will first ask your age, whether you have any other diseases, what exactly the symptoms feel like and when they occur. They will also ask about cardiovascular disease in your family and about risk factors such as smoking. They will do a physical examination of your chest, too.

If the doctor suspects you have CAD, the most important examination is an electrocardiogram (ECG). This is done either while you're resting or while you're exercising. It is also possible to do an ultrasound scan of the heart (echocardiography) or use another imaging technique to examine the heart. Whether further heart tests are needed, and what kind, will depend on your age, any other medical conditions you have, and your symptoms.

To assess the risk of complications and make a treatment plan, your doctor will suggest having several other tests. The typically involves:

  • Measuring blood pressure: Blood pressure is measured because if someone who has CAD also has high blood pressure, the CAD is more likely to lead to complications.
  • Physical examinations: Examinations such as listening to the heart or feeling the liver can help to find out whether you might have other conditions such as heart failure or heart valve problems.
  • Test for metabolic disorders: A blood sample is usually taken as well, to look for any metabolic disorders such as type 2 diabetes or to measure your cholesterol level. Type 2 diabetes can greatly increase the risk of developing complications.

In the long term, it's a good idea to have regular check-ups with your family doctor to keep an eye on how the CAD develops, adjust treatment, and discuss your personal goals and any problems. Check-ups every 3 to 6 months are recommended.


In Germany, people who have statutory health insurance are entitled to one general health check-up between the age of 18 and 35, and then one every three years after that. The aim of this check-up is to detect early signs of cardiovascular disease, diabetes and kidney problems. It involves things like having your blood pressure taken, as well as blood and urine tests.


The treatment for CAD will depend on things like whether it's acute or chronic. Long-term treatment is important in both cases, to prevent complications and symptoms.

Treating a heart attack

In the event of a , medication is given quickly to stop the blood clotting. The blocked blood vessel is then usually widened in hospital using a cardiac (heart) to get the blood flowing again as soon as possible. Known as angioplasty, this procedure is done by feeding a thin, flexible tube (catheter) into the affected blood vessel and pushing it all the way to the blocked area – usually through an artery in the groin or, less often, in the wrist. A balloon at the tip of the can then be inflated to widen the blood vessel. A tiny wire mesh tube called a stent is then placed in the blood vessel to prevent it from becoming narrow again. Some heart attacks are only treated with medication.

Illustration: Cardiac (heart) catheter with balloon and stent

Treating chronic CAD

Medication can reduce the symptoms and restrictions in everyday life caused by stable CAD. Beta blockers, channel blockers and nitrates are used for this purpose. If that doesn't help enough, doctors often try to widen the narrowed coronary artery with a procedure using a cardiac .

Bypass surgery might also be an option, depending on which and how many blood vessels are affected. This involves taking a blood vessel from elsewhere in the body and using it to redirect blood around the blocked coronary artery (bypassing it). Whether surgery is a suitable treatment option will depend on things like your age and any other medical conditions you may have.

Long-term treatment

There are things you can do on your own to help prevent complications like a (further) or heart failure: for example, eating a healthy diet and getting enough exercise. If you smoke, you could try to give it up. There are also a number of medications that can prevent complications and increase life expectancy. These mainly include:

  • Low doses of acetylsalicylic acid (the drug in medicines like "Aspirin") to prevent blood clots
  • Statins to protect the blood vessels

Depending on your personal situation and other medical conditions you have, further medications may be considered. People with CAD are also advised to have a yearly flu jab. This is because the flu can be particularly severe in people with CAD. Studies have shown that a flu jab after a can prevent deaths.


There are many different ways for people who have CAD to improve their physical fitness and quality of life, and also prevent complications. They include the following:

  • Cardiac rehabilitation (follow-up rehabilitation treatment)
  • Exercising with other heart patients

Cardiac rehabilitation programs often include a combination of exercise, learning how to deal with the disease and risk factors, as well as psychological and social advice and support. Personal issues regarding work, family, relationships and psychological stress might be discussed too. Loved ones can also participate in the rehabilitation program. The program is led by a team of specialists from various fields, including medicine, physical therapy, nutritional sciences and psychotherapy.

Cardiac rehabilitation is particularly recommended for people who

Your doctor can help you submit an application for cardiac rehabilitation to the insurance provider in question. In Germany, this will typically be a statutory health insurer or pension fund.

After doing a rehabilitation program, you can take part in an outpatient exercise group for heart patients. These groups meet at least once a week. The training is supervised by doctors and led by health care professionals. As well as doing specially tailored group exercise sessions, the participants are also informed about things like diet and losing weight. A list of these groups is available from the regional organizations of the "German Society for Prevention and Rehabilitation of Cardiovascular Disease (DGPR)." The participation in one of these groups can also be prescribed by doctors as "Rehabilitationssport" (sports for rehabilitation purposes).

Everyday life

Some people who have CAD may feel guilty because they think they should have done more for their health. But personal lifestyle is only one factor. Further key factors include your age, genes, and other things that can hardly be influenced.

People who have heart problems are often given a lot of well-meant advice, and may sometimes feel like they need to change their entire way of living. But that is almost impossible. It is more helpful to set one goal after the other, like taking more exercise.

It can be distressing to live in constant fear of having a . But good treatment with medication can reduce the risk as much as possible. It is important to be aware of the signs of a and to seek immediate medical help if necessary.

Many people who have CAD wonder whether they might have a if they have sex. Like any kind of strenuous physical activity, sex somewhat increases the risk of a for a short time, but the overall risk is still low. Regularly doing low-intensity endurance exercise could reduce the risk of having a after physical exertion.

A is usually a life-changing experience. It is not uncommon for people to feel down or even develop requiring treatment after having one. But heart attacks often have fewer serious long-term effects than people first think. It is important not to feel discouraged, but instead learn how to live with CAD. There are effective treatments for . Cardiac rehabilitation programs sometimes offer psychological support too.

Further information

Anyone with CAD who has statutory health insurance in Germany can participate in a structured disease management program (DMP). These programs aim to improve quality of life and ensure high-quality care. The best way to sign up for a DMP is by contacting your health insurer.

Anderson JL, Morrow DA. Acute Myocardial Infarction. N Engl J Med 2017; 376(21): 2053-2064.

Bundesärztekammer (BÄK), Kassenärztliche Bundesvereinigung (KBV), Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF). Nationale Versorgungsleitlinie Chronische KHK. Langfassung. AWMF-Registernr.: nvl-004. 2019.

Canto JG, Shlipak MG, Rogers WJ et al. Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain. JAMA 2000; 283(24): 3223-3229.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on February 18, 2022

Next planned update: 2025


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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