Pulmonary Embolism

A blockage in an artery in the lungs, usually by a blood clot from the leg. It's a medical emergency.

Blood clotsLungsEmergencyLast updated: 21 October 2026

Quick Summary

Primary Symptoms

Sudden breathlessness, sharp chest pain that's worse when breathing in, fast heartbeat, coughing blood and fainting.

Common Treatments

Emergency treatment with anticoagulants; clot-dissolving treatment for severe cases.

Risk Factors

Deep vein thrombosis, recent surgery, immobility, cancer, pregnancy and hormone medicines.

OverviewSymptomsCausesTreatmentFAQ

Overview

Most pulmonary embolisms start as a DVT in the leg. Part of the clot breaks off and travels through the heart to the lungs.

It can be life-threatening, but prompt treatment works well. Call 112 for sudden breathlessness or chest pain.

Symptoms

Sudden breathlessness

May come on quickly.

Chest pain

Sharp, worse on breathing in.

Coughing blood

Sometimes.

Fainting or fast heartbeat

Signs of a large clot.

Causes & Risk Factors

Biological Causes

A blood clot (usually from the deep veins of the legs) lodging in the pulmonary arteries.

Key Risk Factors

  • DVT Leg clots are the main source.
  • Surgery and immobility Especially after hip or knee surgery.
  • Other risks Cancer, pregnancy, birth control pills and inherited clotting conditions.

Management & Treatment

01. Emergency care

Anticoagulants started straight away.

02. Clot removal

Clot-dissolving medicines or procedures for severe cases.

03. Long-term treatment

Anticoagulants for at least three months.

Frequently Asked Questions

How is it diagnosed?
With a CT pulmonary angiogram, along with blood tests such as D-dimer.
Can it be prevented?
Moving after surgery, preventive anticoagulants in hospital, and treating DVT.
Will I recover?
Most people recover well with treatment.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.