Pulmonary embolism

Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

A pulmonary embolism is a blockage in one of the lung’s arteries, usually caused by a blood clot from a deep vein thrombosis. Learn about the symptoms, causes and treatment.

What is a pulmonary embolism?

A pulmonary embolism is caused when one of the blood vessels (arteries) in your lungs becomes blocked. The blockage is usually due to one or more blood clots, which can be large or small.

When the clot is larger, and around the centre of the lung, it’s called a ‘massive PE’. This is a serious condition which can be life-threatening, so prompt treatment is crucial.

Pulmonary embolism causes

The majority of pulmonary embolisms are caused by deep vein thrombosis (DVT). This is when a clot forms in a deep vein in your legs. Sometimes it will break off and travel up the vein to your lung, causing a PE.

Who is at risk of pulmonary embolism?

  • You've previously had DVT or PE

  • You've been in bed for a long time because of an illness or surgery

  • Long trips when you’re sitting in a cramped position for at least six hours (e.g. plane or car trips)

  • You’re pregnant or in the first six weeks after the birth of your child

  • You take the combined oral contraceptive pill or HRT

  • You have cancer

Pulmonary embolism symptoms

In many cases, people who have a pulmonary embolism have no symptoms at all, but for those who do, the symptoms usually start suddenly.
They will vary depending on the size of the clot and your state of health. For example, if you’re older or have an existing medical condition, the symptoms are likely to be worse than if you’re fit and healthy.

Symptoms may include:

  • Chest pain

  • Breathlessness

  • Raised temperature

  • Coughing up blood

  • Fast heart rate

  • Symptoms of DVT, like pain and tenderness in the calf muscle or a swollen leg or foot

Symptoms of a massive PE can be different. These can include:

  • Chest pain in the centre of the chest (behind the breastbone)

  • Extreme breathlessness

  • Feeling faint/collapsing

  • A drop in blood pressure

In rare cases, a massive PE can cause a cardiac arrest, when the clot stops the heart from pumping. This is very unusual, but it can be fatal.

Treatment for pulmonary embolism

While PE can be a serious medical condition, most people make a full recovery as long as it's spotted and treated quickly. If doctors suspect you have a PE, they may give you an anticoagulant (a drug that prevents blood clots) even before it has been diagnosed.

If a pulmonary embolism is confirmed, you'll need further treatment to help keep the clot from getting bigger and to prevent further clots from forming. Anticoagulant injections are usually needed for several days, followed by tablets for several months.

In more serious cases of PE, treatments may include:

  • Clot dissolvers, called thrombolytics, which help to dissolve the clot

  • Surgery to remove the clot if it is very large and life-threatening

  • A vein filter, inserted into the body’s main vein to stop further clots from reaching the lung

How to prevent a pulmonary embolism

As a PE is usually caused by DVT, take the following steps to reduce your risk:

  • Try to get up and walk around the hospital ward as soon as possible after surgery.

  • If you're on a long flight, get up and walk around regularly, wear loose fitting clothes and bed socks.

  • If you’re having surgery and are at a higher risk of DVT, doctors may recommend that you take preventative blood-thinning medication before and after the surgery.

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi