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

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:

Call 999 or go to A&E if:

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.

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.