About angina

Angina is a heart condition caused by the blood supply to the heart muscle being restricted. This is usually as a result of the arteries that supply the heart muscle becoming hardened and narrowed.

It's a common condition among older adults. The exact number of people living with angina varies greatly across UK studies. A GP will see, on average, four new cases of angina each year.

Find out more about the diagnosis of angina

Symptoms of angina

Recognised symptoms of angina are:

  • chest pain or discomfort, which may spread to the arms, neck, jaw, stomach or back
  • a dull pain, ache or ‘heavy’ feeling in your chest
  • chest pain or discomfort which feels like indigestion but makes you feel generally unwell
  • feeling sick, sweaty, breathless, light-headed, dizzy or generally unwell with pain and discomfort in your chest

Find out more about the symptoms of angina

Types of angina

The two main types of angina are stable angina and unstable angina.

Stable angina

If you have stable angina, symptoms will usually develop gradually over time and follow a set pattern. For example, you may only experience symptoms when climbing stairs or if you are under a lot of stress.

Symptoms of stable angina usually only last for a few minutes and can be improved by resting and/or taking medication called glycerine trinitrate (GTN).

Stable angina isn't life threatening on its own but is a sign that your arteries supplying blood to your heart muscle are narrowing. This means you have an increased risk of experiencing more serious conditions, such as a heart attack.

Unstable angina

If you have unstable angina, symptoms can develop rapidly and can persist even when you are at rest. They may continue for some time.

Symptoms of unstable angina might also not respond to treatment with glycerine trinitrate (GTN).

You may experience symptoms of unstable angina after previously having symptoms of stable angina. However, unstable angina can also occur in people who haven't had stable angina.

Unstable angina should be regarded as a medical emergency because it is a sign that the blood supply to and the function of your heart is compromised, increasing your risk of having a heart attack.

There are many different options for treatment for unstable angina but it can often be treated with medication and/or types of surgical interventions.

Treating angina

The main aims of treatment of angina are to:

  • control your symptoms of angina
  • allow you to maintain as high a level of activity as possible
  • improve your quality of life
  • prevent any worsening of the narrowed coronary arteries


Medication is usually the most effective management for angina and various types can be used. 

Find out more about medication used to treat angina


A procedure may be recommended if your symptoms don't respond to other forms of treatment.

There are two types of procedures that are used to treat angina:

  • coronary artery bypass graft (CABG) - where a section of blood vessel is taken from another part of the body and used to re-route the flow of blood past a blocked or narrow section of artery
  • percutaneous coronary intervention (PCI) also known as a coronary angioplasty - where a narrowed section of artery is widened using a balloon and a tiny tube called a stent

Find out more about procedures used to reduce the symptoms of angina

Causes of angina

Most cases of angina are caused by atherosclerosis, which is a condition where the arteries become hardened and narrowed due to a build-up of fatty substances that are known as plaques. This can restrict the blood supply to the heart muscle and trigger the symptoms of angina.

Conditions that affect the normal flow of blood, such as atherosclerosis, are known as cardiovascular diseases (CVD).

Find out more about causes of angina

Living with angina

Living with a condition such as angina can cause feelings of stress and anxiety in some people, which can lead to symptoms of depression.

You may be feeling depressed if during the last month you have:

  • often felt down, depressed or hopeless
  • little interest or pleasure in doing things

It's important that you speak to your GP if you think that you have depression. Depression does not only affect your mental health, it can also have an adverse effect on your physical health as well.

Find out more about depression

Find out more about living with a heart condition on the British Heart Foundation website


It's recognised that you can considerably reduce your risk of worsening angina and from developing further complications by making changes to your lifestyle as well as taking medications that are prescribed.

If you've been diagnosed with any form of heart disease, you should see your GP at least annually for a health check. This will ensure you are managing your condition as well as it can be.

Find out more about prevention of angina on the British Heart Foundation website

Symptoms of angina

Most commonly, angina pain can spread to your:

  • throat or neck
  • jaw
  • shoulders
  • left or right arm, or both (going down the inside of the arms)
  • back or stomach

Such symptoms usually follow a period of physical activity or emotional stress. In some cases, the pain can also develop after eating a heavy or spicy meal or during cold weather.

Factors that can cause the symptoms of angina to occur are called angina triggers.

Some people with angina may also experience symptoms of:

  • breathlessness
  • feeling sick
  • feeling unusually tired
  • dizziness
  • restlessness

Often these symptoms are predictable and will be relieved with rest or for those who know they have angina, by using glycerine trinitrate (GTN).

Unstable angina

Unstable angina happens when the blood supply to the heart is severely restricted. This type of chest pain can happen at rest or during the night.

This can be angina that is experienced for the first time or a sudden worsening of existing angina.

The symptoms of unstable angina are the same as those of stable angina, but they do not follow the usual pattern.

For example, in unstable angina the symptoms:

  • can develop without any angina triggers being present
  • can persist even when you are resting
  • can last longer than five minutes
  • may not respond to treatment with GTN

This may be an indication of a worsening condition and you should see your doctor urgently.

It's likely that you'll be admitted to hospital or referred to a Rapid Access Chest Pain Clinic for re assessment.

If your GP cannot see you within 24 - 48 hours and these attacks are coming on more frequently and are not readily relieved by GTN spray then you should call the NHS 24 111 service for free and ask for advice.

Causes of angina

Like all the body’s organs and tissues, your heart needs a constant supply of oxygen-rich blood to function normally. It gets this supply through the three main coronary arteries.

These are the: 

  • right coronary artery
  • left coronary artery
  • circumflex artery

In some people, a fatty deposit (atheroma) builds up in the lining of the arteries throughout the body over a number of years.
This deposit narrows the artery and eventually reduces the amount of blood that can get through. 

This process is called atherosclerosis.

Unstable angina

If the deposit or plaque bursts it can become more unstable and will interfere with the normal flow of blood. This may cause a blood clot to form.

This blood clot can enlarge and severely narrow or block one of the coronary arteries and seriously reduce the blood supply to the heart.

This can trigger the symptoms of unstable angina.

Risk factors

Anything that causes the coronary arteries to narrow is a risk factor for both stable and unstable angina.

Several risk factors are explained below. It's worth noting that they can often be inter-related.

High blood pressure

Your arteries are designed to pump blood at a certain pressure. If that pressure is exceeded (high blood pressure), the artery walls will be damaged.

High blood pressure can be caused by:

  • being overweight
  • drinking excessive amounts of alcohol
  • smoking
  • prolonged stress 
  • a lack of exercise
  • a diet high in salt

For reasons that are not fully understood, high blood pressure is more common among people of Afro-Caribbean and south Asian (Indian, Pakistani and Bangladeshi) origin.

A tendency to develop high blood pressure also often runs in families. This is known as a genetic or familial predisposition. However, it can also be due to lifestyle habits picked up through generations, for example, seasoning meals with copious amounts of salt.

Find out more about preventing high blood pressure

High-fat diet and cholesterol

Cholesterol is a type of fat that is essential for the functioning of the body. It helps produce hormones, protects nerve endings and makes up cell membranes (the walls that protect individual cells).

There are two main types of cholesterol:

  • Low-density lipoproteins (LDL) known as the bad type of cholesterol - carry cholesterol from your liver to the cells that need it
  • High-density lipoprotein (HDL) known as the good type of cholesterol - carry cholesterol away from the cells and back to the liver to be broken down

Too much bad cholesterol (LDL) in your blood can cause fatty material to build up in your artery walls. The risk is particularly high if you have a high level of bad cholesterol and a low level of good cholesterol.

Lack of exercise

A lack of regular exercise can raise your blood pressure and increase your risk of developing type 2 diabetes.

Both of these factors increase your risk of developing angina.

Find out more about keeping active


Drinking excessive amounts of alcohol will also increase your risk of developing angina.

Regularly exceeding the recommended alcohol limits will raise your blood pressure and your cholesterol level, both of which are risk factors for angina.

Find out more about drinking alcohol responsibly


Smoking can damage the walls of your arteries. If your arteries are damaged by smoking, blood cells called platelets will form at the site of the damage in an attempt to repair it. This can cause your arteries to narrow.

Smoking also decreases your blood's ability to carry oxygen around your body, which increases the chances of a blood clot occurring.

If you smoke, learn some effective ways to quit or phone Quit Your Way Scotland on 0800 84 84 84 (8.00am to 10.00pm, 7 days).


If you have poorly controlled diabetes, the excess amount of glucose in your blood can damage the walls of your arteries.

Speak to your GP or practice nurse if you are concerned about your blood glucose levels and always attend your diabetic follow up appointments.

Find out more about diabetes


Arteries tend to get narrower over time. Therefore, the older you are, the more likely it is that your arteries will have narrowed, increasing your risk of developing angina.

Family history

Heart disease can run in families, so if you have a first-degree relative (mother, father, brother or sister) with a history of heart disease or angina, your risk of developing angina is increased.

Find out more about this on the British Heart Foundation website 

Diagnosing angina

To diagnose angina, an assessment of your overall situation is necessary. This is done either in a Rapid Access Chest Pain Clinic (RACPC) or by your GP if the necessary tests are available.

This assessment involves:

  • asking questions about what brings on the pain and what relieves it - ruling out other possible causes of pain
  • checking for any risk factors that may be contributing to your angina
  • measuring your weight and blood pressure
  • taking blood - to check your haemoglobin for anaemia, your blood glucose for diabetes and your cholesterol level
  • taking an ECG (electrocardiogram) – that gives a record of the electrical activity of the heart when you are at rest

Electrocardiogram (ECG)

An electrocardiogram (ECG) records the rhythms and electrical activity of your heart.

A number of electrodes (small sticky patches) are placed on your arms, legs and chest.

The electrodes are connected to a machine that records the electrical signals of each heartbeat.

Find out more about having an ECG

Exercise tolerance test (ETT)

An exercise tolerance test (ETT) is similar to an ECG but it is carried out when you are exercising, usually on a treadmill or an exercise bike.

It's not a test to see how fit you are but measure how much exercise your heart is able to tolerate before the symptoms of angina are triggered.

This information is useful for assessing how severe your angina is likely to be.

Find out more about an ETT on the British Heart Foundation website

Myocardial perfusion scan (MPS or Myoview)

A myocardial perfusion scan (MPS) is an alternative test to an ETT that can be used if a person is unable to exercise or when the results of an ETT are unclear.

MPS involves injecting a small amount of a radioactive substance into your blood. A special camera (gamma camera) is used to track the substance as it moves through your blood vessels and into your heart.

This allows healthcare professionals to determine how well blood is reaching your heart muscle.

MPS is usually carried out both at rest and when your heart is under stress. Medication is used to stress the heart during the test to see how well it copes with the added workload.

Find out more about an MPS on the British Heart Foundation website

Coronary angiography

A coronary angiogram is a test that can be used to identify whether your coronary arteries are narrowed and how severe any blockages are.

During an angiogram, a catheter (a thin, flexible tube) is passed into an artery in your groin or arm, and X-rays are used to guide it into your coronary arteries. A dye is injected into the catheter to highlight the arteries supplying blood to your heart muscle. A number of X-ray images are taken that will highlight any narrowing's or blockages.

Coronary angiograms carry a small risk of serious complications, such as a stroke or a heart attack, which is estimated to be around 1 in 500. Although this risk is small, healthcare professionals are usually unwilling to perform an angiogram unless the benefits of the procedure outweigh the potential risks.

Therefore, it is likely that you will only be referred for a coronary angiogram if:

  • the diagnosis of angina remains unclear
  • your angina symptoms persist despite treatment and/or you are thought to be at significant risk of having a heart attack or stroke 
  • you're waiting for other heart procedures or surgery, and it may be important to assess your coronary arteries before this takes place

Find out more about having a coronary angiogram

Unstable angina

If unstable angina is suspected, you will be admitted to hospital. Depending on the severity of your symptoms, you may be placed in a general ward or in the intensive care unit (ICU).

You will be given an ECG as soon as you arrive at hospital to quickly assess whether your heart has been significantly damaged.
Blood tests will also be carried out to help identify increased enzyme levels (troponin), which are known to be released when the heart is damaged.

A coronary angiogram may also be performed to assess the size and location of the blockage in your coronary artery.

Due to the urgent need to prevent serious complications arising from unstable angina, treatment may be started before all test results are available.

Medicines for angina

The main aim in treating angina is to control the symptoms and:

  • allow you to maintain as high a level of activity as possible
  • improve your quality of life
  • prevent worsening of the narrowed coronary arteries (important when deciding on your treatment plan)

If you have angina frequently it's likely that you'll need two or more drugs to relieve the pain, to prevent the pain from developing and to protect you from serious events such as heart attacks.

Different groups of drugs work differently and have different side effects. It is a case of finding the most effective ones for you with the fewest side effects. You may need to take a combination of drugs as this is often most effective.

It's important you take your drugs as prescribed. Speak to your doctor or phone the NHS 24 111 service for advice if a dose is missed or repeated.

If your angina is not being controlled with drug therapy, it is likely that your doctor will refer you to a cardiologist.

You can find information on some commonly used drugs for treating angina below.

Glyceryl Trinitrate (GTN)

GTN is used to relieve angina pain actively as it happens.

It's absorbed in the mouth, under the tongue (sublingual) making it effective in 1 to 2 minutes, lasting 20 to 30 minutes.

Using GTN

GTN can be used in tablet or spray form, whichever you prefer.

Explain to those around you about using your GTN. This will help alleviate any fears they have and give you reassurance that they will be able to help if needed.

Accepting the use of your GTN spray or tablets can take away fear of pain coming on.

GTN can also be used prior to doing an activity that you might be afraid will bring angina on. If you use your GTN and it wasn’t necessary, the worst thing likely to happen to you is a headache.

There's no limit to the number of occasions you can take GTN. It's not addictive and your body will not become used to it with frequent use.

How to use your GTN spray

If experiencing pain or breathlessness:

  1. sit down
  2. take a deep breath
  3. take 2 puffs of your GTN
  4. wait 5 minutes

If pain or breathlessness remains:

  1. take 2 puffs of your GTN
  2. wait 5 minutes

If still experiencing pain or breathlessness then call your GP or dial 999.

Side effects of GTN

Side effects of GTN include headaches and dizziness.


Antiplatelets reduce your risk of heart attack or stroke by interfering with the normal clotting mechanism in the blood, making it less likely to form clots.

Everyone with coronary artery disease should be prescribed an antiplatlet, usually aspirin.

Aspirin occasionally upsets the stomach causing indigestion. This may be avoided by taking your tablet with or after meals but speak to your doctor if you continue to suffer.

In the event of true aspirin intolerance or allergy, clopidogrel 75mg daily can be considered as an alternative for some people.

Dipyridamole is also an antiplatelet, more commonly associated with heart valve problems.


Beta-blockers are used to treat high blood pressure and angina.

Beta-blockers reduce the work your heart has to do by slowing down the heart rate and lowering the blood pressure. This makes them effective in reducing the number of angina attacks as well as allowing you to be more active.

Find out more about beta-blockers.

Statins – cholesterol lowering drugs

Your doctor may also ask you to take tablets to lower your cholesterol, called statins.

Even if your cholesterol is not especially high your doctor may prescribe tablets as a preventative measure.

Frequent stomach pains or muscle pains should be reported to your doctor when taking statins. You will also have to make changes to your diet to lower your cholesterol most effectively

Find out more about statins.

ACE inhibitors

ACE inhibitors help to relax the arteries, lowering blood pressure and reducing the work the heart has to do.

They are used to treat high blood pressure as well as other heart problems, particularly when there has been some damage to the heart muscle such as from a heart attack.

They are also known to act preventatively in reducing the risk of heart attacks and stroke in people who have coronary heart disease.

Find out more about ACE inhibitors on the Blood Pressure UK website

Angiotensin receptor blockers (ARBs)

Angiotensin receptor blockers (ARBs) are mainly used for angina when ACE inhibitors are not suitable.

They act in much the same way as ACE inhibitors and may be used in combination with them where there's been some previous damage to the heart muscle, such as from a heart attack.

Find out more about ARBs on the Blood Pressure UK website


Nitrates are used to treat angina and heart failure as they reduce the amount of work the heart muscle has to do. They open up the arteries by relaxing the muscle in the artery wall, causing the blood vessels to dilate.

Nitrate tablets

Some are ‘slow release’ or ‘modified release’ tablets. When you swallow these they gradually release a steady amount of nitrate, which is absorbed into the body.

They should be taken at the times prescribed in order for them to work effectively:

  • Isosorbide Mononitrate - usually taken once a day
  • Isosorbide Dinitrate - usually taken at 12 hourly intervals (twice a day).

If nitrate stays in your bloodstream all the time, your body becomes used to it and the nitrate then has much less of an effect. To overcome this ‘tolerance’ you will be prescribed medication so that your blood stream will be free of nitrate for a few hours each day. 

Isosorbide dinitrate can also be used to relieve pain during an attack in different forms.

Nitrate patches

Some come as skin patches or ointments, which release a steady amount of nitrate into the bloodstream through the skin.

Patches should be applied to the chest or back and not directly over the heart.

Only one patch should be used a day, which should be removed at night unless specifically being used to combat nighttime angina.

Apply the patch to a different area of skin every time and don't apply the patch to inflamed or cracked skin (the medicine can be absorbed too rapidly).

Calcium channel blockers

Calcium channel blockers help to relax the arteries, lowering blood pressure and reducing the work the heart has to do. This makes them effective in reducing the number of angina attacks as well as allowing you to be more active.

Sometimes calcium channel blockers, such as Diltiazem, are used in combination with beta-blockers to control angina.

Sometimes they are used for people who are not able to take beta-blockers. For example, Verapamil is used in place of a beta-blocker when someone has severe COPD (chronic obstructive airways disease) or asthma.

Calcium channel blockers tend to be less effective if you smoke.

Potassium channel activators

Potassium channel activators work partly like a nitrate and partly like a calcium channel blocker.

They tend to be used in combination with other drugs and can be helpful when angina is not well controlled by other drugs.

Unstable angina

If you have unstable angina (where symptoms develop rapidly and persist even when you are at rest), when admitted to hospital you'll be given medication to prevent blood clots developing and reduce your risk of having a heart attack.

This will usually be aspirin, used for its blood thinning abilities rather than as a painkiller, unless there is a reason you are unable to take aspirin such as having a history of liver disease.

You may also be prescribed another blood-thinning medication called clopidogrel, which you may need to take for a number of months.

Some people are only prescribed one of these medications.

You may also be given an injection of an additional blood thinning medication.

If the risk is moderately high, a coronary angiogram may be carried out to assess the size and location of the blockage in your coronary artery. If the blockage is significant, a CABG or a PCI can be performed.  

Surgeries for angina

Medication is the optimum treatment for angina. The following interventions are designed to relieve the symptoms of angina rather than cure it or the cause of it.

Therefore, it's important to remember that drug treatment and working on reducing risk factors will still be necessary to prevent symptoms recurring.

Percutaneous coronary intervention (PCI)

PCI involves stretching narrowed areas of coronary arteries to improve the blood flow. 

It's performed in a similar way to an angiogram (cardiac catheterisation) then stretching the narrowed coronary artery with a tiny balloon which is at the tip of the catheter.

In the majority of cases, a metal stent will also be placed in the artery (angioplasty and stent). A stent is a cylinder of metal mesh, which acts like a scaffold to keep the artery open and prevents the narrowing coming back.

The artery heals around the stent making it a permanent part of the artery. You won't be aware that it's there.

Sometimes stents can be used which slowly release drugs directly to the narrowed area to help prevent the problem recurring. These are called Drug Eluting Stents (DES) and are only considered for use in certain cases, such as for a person with diabetes.

Coronary artery bypass

Surgical treatment used to treat angina is commonly referred to as a ‘bypass’.

Not everyone with angina will be suitable for surgery. Your cardiologist will discuss the options with you if it's felt that you would benefit. You will have the chance to ask questions and decide whether or not you want to proceed.

Bypass surgery can be performed on more than one narrowed coronary artery hence the terms ‘double’ and ‘triple’ bypass surgery.

It involves opening the chest and bypassing the affected narrowed artery by using a vessel from the chest or leg to provide a new route for the blood so that the area of muscle has a better blood supply.  

Find out more about heart surgery

Last updated:
06 May 2022