Pulmonary embolism

What is a pulmonary embolism?

A pulmonary embolism is a condition where one or more blood clots come from another part of the circulation, like the leg veins, and migrate (embolise) so that they block the arteries in the lungs (the pulmonary arteries), restricting blood flow to that area of the lung.

What are the symptoms of a pulmonary embolism?

Symptoms of pulmonary embolism can be mild or severe, depending on the size of the embolism, and can come on suddenly.

These symptoms can include:

• chest pain or heavy feeling in the chest
• coughing (with or without coughing up of blood)
• fainting
• feeling light-headed or dizzy
• breathlessness or rapid breathing
• increased or irregular heart rate
• swelling of the leg(s), most often in the calf muscle (this is usually due to a clot forming in the legs or other areas, less often for the pulmonary embolism itself)
• fever and sweating
• low blood pressure

What causes a pulmonary embolism?

Pulmonary embolism occurs when a blood clot in another area of the body breaks loose and travels to the lung through the bloodstream.

The most common cause of pulmonary embolism is deep vein thrombosis (DVT). This is where a clot forms in the deep veins of the leg, or sometimes the arm.

The main cause of DVT is slowed blood flow that results in blood clotting. This can occur due to injury, inflammation, infection, surgery, or extended periods of sitting or lying. A long-haul flight can be a risk for developing DVT in some people.

How is a pulmonary embolism diagnosed?

It can be hard to diagnose pulmonary embolism as the symptoms can mimic other heart or lung conditions.

Pulmonary embolism may be diagnosed through a series of tests including:

• blood tests
• pulse oximetry (a test where a probe on the finger can tell the level of oxygen in the blood)
• electrocardiogram (ECG)
• chest x-ray
• computed tomographic pulmonary angiography (CTPA), a CT scan that takes pictures of the pulmonary arteries that run from the heart to the lungs
• ventilation-perfusion scan (V/Q scan), which measures air and blood flow in the lungs

How is a pulmonary embolism treated?

A major pulmonary embolism is a medical emergency and can be fatal, so treatment should be sought immediately.

Treatment for pulmonary embolisms may include:

• anticoagulant medicines (also known as blood thinners) or thrombolytic (also known as fibrinolytic) medicines to dissolve the clot
• inferior vena cava filter (IVC) – a filter that is inserted in the inferior vena cava (a large vein that transports blood to the heart) to catch the clot before it travels to the heart and lungs
• pulmonary embolectomy – a type of surgery to remove the clot(s) in very serious cases

How can a pulmonary embolism be prevented?

The best way to prevent pulmonary embolism is to reduce your risk of developing DVT.

Reducing your risk of DVT may include:

• maintaining a healthy diet
• exercising regularly
• regularly moving your arms and legs if sitting or standing for long periods (including on long-haul flights)
• managing your weight
• quitting smoking
• drinking plenty of water
• talking to your doctor if you have a family history of blood clots
• following any blood clot prevention strategies as advised by your doctor

How long does it take to recover from a pulmonary embolism?

Recovery will depend on individual circumstances, including the severity of the pulmonary embolism.

After a pulmonary embolism you may begin to feel better within a few days of treatment, though full recover may take weeks or months.

Long term damage that requires ongoing treatment may occur after a pulmonary embolism, though this is rare.