Introduction 

A pulmonary embolism is a blockage in the pulmonary artery, which is the blood vessel that carries blood from the heart to the lungs.

This blockage – usually a blood clot – is potentially life threatening, as it can prevent blood from reaching your lungs.

Signs and symptoms

The symptoms of a pulmonary embolism can sometimes be difficult to recognise because they can vary between individuals. However, the main symptoms include:

  • chest pain – a sharp, stabbing pain that may be worse when you breathe in
  • shortness of breath – this can come on suddenly or develop gradually
  • coughing – this is usually dry, but may include coughing up blood or mucus that contains blood
  • feeling faint, dizzy or passing out

You should visit your GP as soon as possible if you have a combination of these symptoms.

If your symptoms are particularly severe, dial 999 immediately and ask for an ambulance.

Read more about the symptoms of a pulmonary embolism and diagnosing a pulmonary embolism.

Why it happens

A pulmonary embolism is often caused by a blood clot travelling up from one of the deep veins in your legs to your heart and lungs.

A blood clot in one of the deep veins of the legs is known as deep vein thrombosis (DVT). DVT can occur for no apparent reason, but it often develops after long periods of inactivity, such as during a long-haul flight or if you are ill in hospital.

DVT can also occur during pregnancy, as a result of some medical conditions, such as cancer or heart failure, or if the wall of a blood vessel becomes damaged.

Read more about the causes of a pulmonary embolism.

How pulmonary embolisms are treated

Pulmonary embolisms are treated with anticoagulant medicines. These stop the blood clot getting bigger while your body slowly reabsorbs it, and reduce your risk of further clots developing.

If you are diagnosed with a pulmonary embolism, you will normally be given regular anticoagulant injections for about five days to begin with. You will also be prescribed an anticoagulant tablet called warfarin to take for several months.

As part of your treatment, you will need to have regular blood tests to check that the dose of warfarin you are receiving is correct. If the dose is too high, you may experience bleeding, and if it is too low, you may have further blood clots.

Keeping mobile will also help you maintain good blood circulation and prevent further blood clots forming.

Read more about treating a pulmonary embolism.

Preventing a pulmonary embolism

There are a number of methods that may be recommended to prevent a pulmonary embolism if you are at risk of developing blood clots.

These include:

  • taking anticoagulant tablets, such as warfarin
  • wearing compression stockings or using compression devices
  • avoiding prolonged periods of inactivity
  • a healthy lifestyle – such as stopping smoking (if you smoke) and eating a healthy, balanced diet that is low in fat and includes plenty of fruit and vegetables

Read more about preventing a pulmonary embolism.

A pulmonary embolism is a blockage in the artery that transports blood to the lungs 

Page last reviewed: 02/10/2013

Next review due: 02/10/2015