Pulmonary embolism What is a pulmonary embolism and what causes it? A pulmonary embolism is caused by a blood clot travelling up from one of the deep veins in your body, usually in the leg. What are the symptoms of a pulmonary embolism? The symptoms of a pulmonary embolism can vary between people and depend on how big the clot you have is. How is a pulmonary embolism diagnosed? If doctors think you’ve had a pulmonary embolism, they will carry out tests with you to confirm this. How is a pulmonary embolism treated? Read about how a pulmonary embolism is treated. We also have information on recovering from a pulmonary embolism and what you should expect. How to reduce your risk of having a pulmonary embolism The best way to prevent a pulmonary embolism is to try and stop blood clots forming in your veins. Find out ways to stop blood clots forming. You must have JavaScript enabled to use this form. Did you find this information useful? Yes No Why? We use your comments to improve our information. We cannot reply to comments left on this form. If you have health concerns or need clinical advice, call our helpline on 0300 222 5800 between 9am and 5pm on a weekday or email them. Leave this field blank Page last reviewed: 24 January 2025 Next review due: 24 January 2028