Heart attack

A heart attack is a serious medical emergency. It happens when the delivery of blood to the heart is suddenly blocked, usually by a blood clot. Lack of blood to the heart can permanently damage the heart muscle if it is not treated urgently to remove the blockage.

Symptoms of heart attack 

Call 999 immediately if you suspect that you or someone you know is having a heart attack.

The symptoms of a heart attack include:

  • chest pain – the pain is usually located in the centre of your chest and can feel like a sensation of pressure, tightness or squeezing
  • pain in other parts of the body – it can feel as if the pain is travelling from your chest to your arms (usually the left arm, but it can affect both), jaw, neck, back and abdomen
  • shortness of breath
  • nausea/vomiting
  • sweating with pale and cool, clammy skin
  • palpitations
  • an overwhelming sense of anxiety (like a panic attack)
  • feeling light-headed
  • feeling tired

A heart attack does not always cause severe chest pain. Even if you’re not sure that your symptoms suggest that you are having a heart attack, you should still call 999 and ask for an ambulance immediately.

Waiting for the ambulance 

It is important to rest while you wait for an ambulance, to avoid unnecessary strain on your heart.

If you know that you are not allergic to aspirin and you have aspirin available, chew (do not swallow) an adult size tablet while you are waiting for the ambulance to arrive.

The aspirin will help to thin your blood and restore the blood flow to your heart.

Causes of heart attack 

Coronary heart disease is the main cause of heart attacks. There are several risk factors of CHD, including the following which you can change:

Other less common causes of heart attack include:

  • drug misuse
  • lack of oxygen in the blood (hypoxia)
  • aneurysm (a weakness in the wall of a blood vessel)

If any of these apply to you, focusing on the risk factors you can change can help to reduce your risk of having a heart attack. In addition, there are risk factors that you cannot change.

Risk factors you cannot change include:

  • family history of a family member having a heart attack at a young age
  • being male
  • being older - the older a person is, the greater the risk of having a heart attack

Treating heart attacks 

A heart attack is a medical emergency. Dial 999 and ask for an ambulance if you think you or someone you know is having a heart attack.

Treatment for a heart attack will depend on how serious it is. Treatment may begin before you get to hospital. 

Two main treatments are:

  • using medication to dissolve blood clots
  • percutaneous coronary intervention (primary PCI). This involves non-surgical widening of the coronary artery, using a balloon to open up the blocked artery from within. A line (cannula) is introduced though a blood vessel in your groin or arm, to reach your heart, to treat the blocked artery

Preventing heart attacks 

To reduce your risk of having a heart attack, you may need to make some changes to your lifestyle. To help keep your heart healthy, you should:

  • stop smoking
  • take regular exercise
  • eat a low-fat, high-fibre diet including whole grains and plenty of fresh fruit and vegetables
  • reduce the amount of alcohol you drink
  • lose weight if you need to


The outlook for people who have had a heart attack can be highly variable, depending on:

  • their age – the older you are, the more likely you are to experience serious complications
  • the severity of the heart attack – specifically, how much of the heart's muscle has been damaged during the attack
  • how long it took before a person received treatment – the longer the delay, the worse the outlook tends to be

In general, around one third of people who have a heart attack die as a result. These deaths often occur before a person reaches hospital or, alternatively, within the first 28 days after the heart attack.

If a person survives for 28 days after having a heart attack, their outlook improves dramatically and most people will go on to live for many years.


Recovering from a heart attack can take several months. During your recovery period, you will receive help and support from a range of healthcare professionals.

The recovery process will usually take place in stages, starting in hospital, where your condition can be closely monitored. The two most important aims of the recovery process are:

  • to gradually restore your physical fitness so you can resume normal activities (known as cardiac rehabilitation)
  • to reduce your risk of another heart attack

Cardiac rehabilitation 

Your cardiac rehabilitation programme will begin when you are in hospital. A member of the cardiac rehabilitation team will visit you in hospital and provide information including:

  • your state of health and how the heart attack may have affected it
  • the type of treatment you received
  • what medications you will need when you leave hospital
  • what specific risk factors are thought to have contributed to your heart attack
  • what lifestyle changes you can make to address those risk factors


The information on this page has been adapted from original content from the NHS website.

For further information see terms and conditions.

This page was reviewed November 2017

This page is due for review February 2020

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