Pulmonary embolism: symptoms, causes and treatment

Pulmonary embolism is a blood clot that blocks an artery in the lungs and needs urgent assessment.

The clot often forms in a deep vein, commonly in a leg, then travels through the bloodstream to the lungs. The blockage can make it harder for blood to pick up oxygen and can strain the heart. Severity varies, but suspected pulmonary embolism should be assessed without delay.

Shortness of breath is a very common presentation of pulmonary embolism. Chest pain and coughing up blood are also common presentations. Symptoms may start suddenly or become noticeable over a short period, and some people also feel faint, have a fast heartbeat or notice leg pain and swelling.

Call emergency services now for severe breathlessness, chest pain with collapse or fainting, blue or grey lips, confusion, or symptoms that are rapidly worsening. These warning signs need emergency assessment regardless of the suspected cause.

Most pulmonary emboli arise when a blood clot in a deep vein breaks free and travels to the lung circulation. Clotting is more likely when blood flow is slow, a blood vessel is injured or the blood has a stronger tendency to clot. The source of a clot is not always obvious at first.

A clot can reduce blood flow through part of the lung and place extra work on the right side of the heart. Prompt treatment aims to stop the clot becoming larger and reduce the chance of new clots. Recovery and follow-up needs vary according to the clot, symptoms and factors that contributed.

Recent immobility, a long journey, surgery, injury, pregnancy and the period after giving birth can raise clot risk. Previous clots, some cancers, inherited clotting conditions, smoking and certain hormone medicines may also matter. These factors help clinicians decide how urgently to investigate and how long treatment may be needed.

Clinicians assess symptoms, vital signs, medical history and clot-risk factors. Tests may include a blood test, an ECG, chest imaging designed to view lung blood vessels, and an ultrasound scan of the legs. The choice and order of tests depends on how unwell the person is and what else could explain the symptoms.

Anticoagulation management uses medicines that reduce the blood's ability to form new clots while the body gradually deals with the existing clot. In selected severe cases, hospital teams may consider treatments intended to break up or remove a clot. Treatment choice balances the danger from clotting with the risk of bleeding.

Take anticoagulant medicine exactly as prescribed and tell every clinician or dentist that you use it. Get urgent advice after a significant injury, bleeding that will not stop, black stools, vomiting blood or a severe new headache.

Follow the activity advice from the treating team and build back gradually as breathlessness improves. Keep follow-up appointments, discuss travel plans and check before starting medicines or supplements that could interact with anticoagulants. Anxiety after a frightening event is common and is worth raising at review.

Some people have ongoing breathlessness, chest discomfort or reduced exercise tolerance after treatment, which should be reviewed. Anticoagulants can cause bleeding, so new or unusual bleeding needs clinical advice. Recurrent chest symptoms or breathlessness should be treated as urgent until assessed.

Move regularly during periods of travel or recovery when it is safe to do so, and follow advice about compression or preventive anticoagulants after surgery or hospital admission. Tell clinicians about previous clots and medicines containing hormones. Individual prevention plans depend on the reason for the clot and current health.

Suspected pulmonary embolism belongs in urgent or emergency care rather than routine self-management. After initial treatment, a GP and hospital team can coordinate medication monitoring, follow-up and referral when ongoing symptoms or clotting risks need specialist input.