Arteries & circulation

Angina

What is angina?

Your heart is supplied with blood by your coronary arteries, which wrap around the outside of the heart muscle and bring it the oxygen it needs to function.

If your coronary arteries are clogged or narrowed, and your heart is not getting enough oxygen, you may experience a kind of chest pain known as angina.

Angina is usually, but not always, caused by coronary artery disease – atherosclerosis that has narrowed or blocked your coronary arteries. It can also be caused by functional problems that restrict blood flow and by blood vessel spasms.

For more information about atherosclerosis and coronary artery disease, take a look at our Atherosclerosis section.

There are four main types of angina:

Stable and unstable angina are caused by coronary artery disease (atherosclerosis of the coronary arteries)
Microvascular angina is caused by problems in the smaller vessels that branch off your main coronary arteries
Variant, or Prinzmetal, angina is caused by coronary artery spasms

People who experience angina describe it as a feeling of pressure or tightness in the center of the chest that, when it’s at its worst, can be like having their chest squeezed in a vise. The discomfort often spreads to the neck, shoulders, back, arms, or jaw.

Attacks of angina can also come with symptoms like tiredness, nausea, shortness of breath, and excessive sweating.

What is stable angina?

Stable angina is the most common type of angina.

The pain of stable angina starts when your heart is working harder than usual – when you exercise or if you’re under emotional stress – and then it recedes, usually within five or 10 minutes, once your heart slows down again.

If you repeat the activity your angina will return.

Episodes of stable angina can also be caused by being very hot or very cold.

Stable angina typically follows a regular pattern – for example, it happens every time you climb the stairs – and it doesn’t get worse over time.

While it is a symptom of underlying coronary artery disease, an episode of stable angina is not a medical emergency and your doctor will advise you that it can usually be controlled by medication and rest.

Stable angina

What is unstable angina?

Unstable angina is chest pain that can come on quite suddenly, certainly with exertion but also at rest. It gets worse over time, lasts longer than an attack of stable angina – perhaps 20 minutes or more – and may not subside with medication or rest.

Unstable angina is a medical emergency. If you have an attack of unstable angina, it means that the blockages in your coronary arteries have reached a critical level and your heart is being acutely deprived of oxygen. You may be at risk of having a heart attack.

Unstable angina

What is microvascular angina?

Microvascular angina is caused by functional problems in the small blood vessels that branch off your main coronary arteries.

The blood vessels don’t widen properly to let blood through, or they spasm, and your heart may become oxygen starved as a result.

If your microvascular angina is caused by lack of dilation in the small vessels, it will tend to flare up when you exercise or when you are stressed, as with stable angina.

If it’s caused by microvascular spasm it can happen any time.

Microvascular angina is much more common in women than men, and it tends to occur after menopause.

What is variant angina?

Variant angina (also known as Prinzmetal angina) occurs in people with no discernable coronary heart disease.

It is caused by coronary artery spasm and can be very painful. Variant angina can happen at any time; attacks are not brought on by exercise, in fact, they most commonly occur during the night between midnight and morning.

Variant angina is quite rare, and it often arises in relatively young, otherwise healthy people – unlike those who are diagnosed with stable or unstable angina.

What causes angina?

All angina is caused by your heart not getting enough oxygen, but the reasons for this vary depending on which type of angina you have.

Causes of stable and unstable angina

The cause of stable angina (by far the most common form) and unstable angina is coronary artery disease – in other words, atherosclerosis of the coronary arteries. The arteries become narrowed or blocked by plaque and your heart is then starved of oxygen as a result.

So, ultimately, the causes of stable and unstable angina mirror the causes of atherosclerosis, which include:

Diet: Animal fats, tropical oils like palm and coconut oil, salt, sugar, and processed foods all contribute to your risk of developing atherosclerotic narrowing of your coronary arteries.
Smoking
Lack of exercise
Drinking too much alcohol
Being overweight
Hypertension
Age: Being over 60 years old
Genetic factors, like familial hypercholesterolemia

If you have stable angina, attacks can be triggered by:

Exercise
Stress
Extreme heat or cold
A large meal

If you have unstable angina, attacks can be triggered by all of these same factors but they can also happen at rest and very suddenly. Unstable angina can be a sign of an impending heart attack and is a medical emergency.

Causes of microvascular and variant angina

Microvascular angina can be caused by narrowing and lack of dilation of the small blood vessels that branch off your coronary arteries, or it can be caused by spasming that has the same effect – the vessels clamp down and don’t let blood through.

Variant angina (or Prinzmetal angina), which is rare, is also caused by blood vessel spasm, but this time it’s your big coronary arteries that are the problem, not the tiny branching vessels.

The causes of the blood vessel spasms that lead to microvascular and variant angina are not clear, but may include:

Stress
Exposure to cold
Medications that constrict your blood vessels, such as decongestants and some migraine treatments
Some illicit drugs, such as cocaine and methamphetamine

What are the symptoms of angina?

The common symptom of all types of angina is chest discomfort or pain. However, the pattern, duration, and severity of the pain differs depending on which type you have.

Symptoms of stable angina:

Chest pain or discomfort, often during exercise or stress
Pain may spread to your arms, neck, or shoulders
The episodes are brief, usually no longer than 5 minutes
You may experience sweating, nausea, dizziness, and shortness of breath
Pain is relieved by resting and/or medication

Symptoms of unstable angina:

Severe chest pain that may occur while resting or only lightly physically active and is often quite sudden in onset
Pain may spread to your arms, neck, or shoulders
The episodes may last for more than 20 minutes and may return
You may experience sweating, nausea, dizziness, and shortness of breath
Pain is not relieved by medication or rest

If you experience these symptoms you should immediately seek medical assistance.

Symptoms of microvascular angina:

Chest pain or discomfort during your normal daily routine as well as during exercise and stress
Pain may spread to your arms, neck, or shoulders
The episodes usually last at least 10 minutes
You may experience sweating, nausea, and dizziness
Pain is only sometimes relieved by medication

Symptoms of variant angina:

Chest pain or discomfort while resting, usually during the night (between midnight and approximately 8:00 am)
Pain may spread to your arms, head, or shoulders
The episodes follow a regular pattern and usually last for 5 to 15 minutes
Sweating, nausea, and dizziness
Pain is relieved by medication

How is angina treated?

Stable and unstable angina

Treatment options for stable angina center on reversal of the atherosclerosis that is blocking your coronary arteries: lifestyle changes, medications, and – if necessary – surgery to reopen clogged blood vessels.

Treatments for stable angina include:

Lifestyle changes: Improve your diet (restrict animal fats, red meat, tropical oils, salt, sugar, and processed foods), exercise more, drink less alcohol, quit smoking
Medication: Medications can open up constricted coronary arteries (nitroglycerin), lower your cholesterol level (statins), manage your blood sugar (if diabetes is a contributing factor), control hypertension, and prevent blood clots
Surgery: A transcatheter procedure can be used to stent areas of acutely narrowed vessels. Surgery to bypass blocked coronary arteries is a final option

For unstable angina, the same treatments apply, but in a different order. Unstable angina is a medical emergency, and first-line treatments are medication and surgery. Long term though, lifestyle changes are very important.

Microvascular and variant angina

The mechanism for the narrowing or spasming of the heart’s microvessels in microvascular angina isn’t well understood and treating it effectively can be very challenging.

The same applies to variant angina.

Leading a healthy lifestyle is always important, and while it’s not key to treating microvascular or variant angina your doctor will probably recommend changes if there’s room for improvement.

Medication can help prevent the coronary artery spasms that are causing the restricted blood flow to your heart and vasodilators can help open the vessels again.

Treatments for microvascular and variant angina include:

Lifestyle changes: Improve your diet, lose weight if necessary, exercise more, drink less alcohol, quit smoking
Medications such as nitroglycerin to open up (dilate) the narrowed or spasming blood vessels
Avoidance of drugs like cocaine, which can cause blood vessel spasms
Avoidance of medications that constrict vessels, such as migraine medications, decongestants, and weight-loss drugs

What are the aims of treatment?

The immediate aims of treatment are to ease the pain and distress caused by angina. The long-term aims are to treat the underlying cause, if known.

In unstable angina, the aim of treatment, both immediate and long-term, is to prevent you from having a heart attack.