NHS Factsheet

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Pulmonary embolism

Read more about a pulmonary embolism, which is when a blood clot blocks a blood vessel in your lungs. It can be life-threatening if not treated quickly.

1 June 2023

Introduction

A pulmonary embolism is when a blood clot blocks a blood vessel in your lungs. It can be life-threatening if not treated quickly.

Check if you have a pulmonary embolism

Symptoms of a pulmonary embolism include:

  • difficulty breathing that comes on suddenly
  • chest pain that's worse when you breathe in
  • coughing up blood

You may also have pain, redness and swelling in one of your legs (usually the calf). These are symptoms of a blood clot, also called DVT (deep vein thrombosis) ↗.

Ask for an urgent GP appointment or get help from NHS 111 if:

  • you have difficulty breathing which comes on suddenly
  • you're coughing up blood

You can call 111 or get help from 111 online ↗.

Call 999 or go to A&E if:

  • you have severe difficulty breathing
  • you feel pain in your chest or upper back
  • your heart is beating very fast
  • someone has passed out

These could be signs of a pulmonary embolism or another serious condition.

Treating a pulmonary embolism

If a GP thinks you've got a pulmonary embolism, you'll be sent to hospital for further tests and treatment.

At hospital, you'll probably be given an injection of anticoagulant medicine ↗ before you get any test results.

Anticoagulants stop blood clots getting bigger and prevent new clots forming.

If tests confirm you have a pulmonary embolism, you'll continue with anticoagulant injections for at least 5 days.

You'll also need to take anticoagulant tablets for at least 3 months.

You should make a full recovery from a pulmonary embolism if it's spotted and treated early.

Reduce your pulmonary embolism risk

A pulmonary embolism often happens when part of the blood clot dislodges itself from your leg and travels up to your lungs, causing a blockage.

There are measures you can take to lower your risk of getting a pulmonary embolism.

If you're being treated in hospital for another condition, your medical team should take steps to prevent DVT (deep vein thrombosis) ↗.

A DVT can occasionally develop on long journeys such as bus, train or air travel. The risk of developing DVT is increased for flights lasting more than 4 hours.

There are things you can do to reduce your risk of getting a travel-related DVT.

Do

  • sit comfortably in your seat and choose an aisle seat if possible

  • wear loose-fitting clothing

  • make sure you have plenty of leg room

  • drink water regularly

  • take regular breaks from sitting

  • bend and straighten your legs, feet and toes every 30 minutes while seated

  • press the balls of your feet down hard against the floor every so often

  • wear flight socks

Don't

  • do not sit for long periods without moving

  • do not drink alcohol

  • do not drink too much coffee and other caffeine-based drinks

  • do not take sleeping pills