A pulmonary embolism is caused by the blockage of a lung artery, after a blood clot from circulating blood has got into the lung. This is an emergency.
At a glance
- A pulmonary embolism is when a blood vessel supplying blood to the lung gets blocked.
- The blockage is usually caused by a blood clot coming from the leg or pelvis.
- The blocked vessel causes a blood blockage between the heart and lung.
- A pulmonary embolism is an emergency and needs to be treated quickly.
- So the emergency number (112) must be called if the person has difficulties in breathing.
Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.
What is a pulmonary embolism?
A pulmonary embolism is caused by the blocking of a lung artery or its branches. This can occur when a large blood clot gets into the lung from the body.
What is pulmonary embolism?
The video below explains more about the symptoms, risk factors and treatment options for pulmonary embolism.
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How can a pulmonary embolism be identified?
If the blocked blood vessel in the lung is only small, there are no or only mild symptoms.
If the embolism occurs in larger vessels in the lung, the following symptoms may occur:
- sudden breathlessness
- chest pains, particularly when inhaling or coughing
- dizziness, numbness or fainting
- fairly rarely: bloody sputum when coughing
Important: With these symptoms, immediate medical help is required. So sufferers or their relatives should always phone 112 and ask for an ambulance with an emergency doctor (NOT the on-call or stand-by GP service called “Ärztlicher Notdienst” oder “Ärztlicher Bereitschaftsdienst”).
What happens with a pulmonary embolism?
If someone hurts themselves and starts to bleed, the body ensures that the bleeding quickly stops and the wound is closed with a blood clot. This reaction by the body is critical. It ensures that the body loses as little blood as possible, that no germs get into the wound, and that the wound can subsequently heal.
However, it is sometimes the case that a blood clot which can block a blood vessel forms in the circulating blood without any external injury. This can result in dangerous complications such as a heart attack, stroke, or pulmonary embolism. This very rarely happens to a healthy person. But certain illnesses and genetic predispositions may increase the risk of a blood clot.
Blood clots that cause a pulmonary embolism can occur at different places in the body. However, they mostly occur in veins in the legs.
If a vessel is blocked by a blood clot, specialists refer to a thrombosis. In the legs, clots often go unnoticed and disintegrate by themselves. However, some thromboses also cause pain and swellings. And occasionally a clot becomes detached and it can then get into the vessels of the lungs.
Fatty deposits, cellular components, air or amniotic fluid when giving birth can, in rare cases, also cause a pulmonary embolism. In the case of an air embolism, an air bubble can get into a blood vessel, for example during an operation. This air bubble can then cause a blockage in the lung.
What are the risk factors for a pulmonary embolism?
Because a pulmonary embolism most commonly occurs as a result of a thrombosis, the risk factors are similar. Some are inherited, i.e. they are genetic, while others evolve during one’s lifetime.
If a person’s parents, or brothers or sisters, have had a thrombosis, it may indicate a family disposition. Such inherited risk factors are, for example, changes to genes that influence blood clotting.
Other factors that increase the risk of an embolism are:
- long periods in bed, for example in hospital, after an operation or an injury
- blood clotting disorders
- a previous deep vein thrombosis
- being over 60 years old
- certain cancers
- cardiac insufficiency
- taking the birth control pill
- hormone therapy for menopause
- bad cases of varicose veins
- certain inflammatory illnesses
- frequent traveling with a lot of sitting down
Important: Each considered separately, most of these risk factors only slightly increase the probability of a thrombosis and embolism. However, the risk increases if multiple factors come together.
How common is a pulmonary embolism?
Pulmonary embolism is rare: around 60 to 70 out of 100,000 have a pulmonary embolism in Germany each year.
How does a pulmonary embolism progress?
A pulmonary embolism can be acute, subacute or chronic:
- Acute: with an acute pulmonary embolism the person suddenly has symptoms such as breathlessness, palpitations, and loss of consciousness.
- Subacute: in some people the symptoms of a pulmonary embolism appear with a couple of hours delay.
- Chronic: with a chronic pulmonary embolism, symptoms which are similar to those of other lung conditions can sometimes appear over months.
How can a pulmonary embolism be prevented?
After an operation, or after a long time during which a person has not been able to move very much, doctors usually advise them to take anticoagulation drugs to avoid a thrombosis.
For people who have been operated on or who are injured and have to spend several days in bed, it is also important to get up again as soon as possible and to move about. Small exercises, such as foot wiggling are also recommended to keep the blood flowing.
Anti-thrombosis stockings (compression stockings) can also be a good idea when there is a high risk of deep vein thrombosis. Because they are tight they exert pressure on the legs, so that the blood flows back to the heart again more quickly.
How is a pulmonary embolism diagnosed?
Symptoms such as breathlessness, chest pain, fainting, and bloody coughing are initial indicators of an acute pulmonary embolism. When one is suspected the doctor begins with detailed questioning and an examination. It is important to produce a reliable diagnosis as quickly as possible.
Various tests are carried out which together enable a diagnosis. These include a blood test, a blood gas analysis, an electrocardiogram (ECG), or examining the lungs using computed tomography (CT). Other imaging methods might be used, such as a catheter examination of the lung artery (pulmonary angiography).
How is a pulmonary embolism treated?
The treatment of a pulmonary embolism depends primarily on the severity of the symptoms. People with symptoms such as palpitations or painful breathing receive intensive medical care and monitoring from the beginning.
If possible, there is an attempt to break the blood clot up through thrombolysis. In this process, special drugs are delivered to the body via an intravenous drip. Thrombolysis is not an option if there is a high risk of bleeding. Sometimes the embolism is then treated by means of an intervention using a catheter.
A catheter is a thin, flexible tube that is pushed through the blood vessel as far as the blocked lung artery. Then it is attempted to break down the clot there. Drugs can also be delivered via a catheter to break down the blood clot in situ.
People with less severe symptoms are normally monitored, but not on the intensive care ward. Their pulmonary embolism is treated with anticoagulants. These are drugs which are injected or taken orally, and which reduce the blood’s ability to form clots.
Drugs that are injected beneath the skin or into the veins take effect after just a few hours. With drugs that are to be taken orally, there is a distinction between coumarins and direct oral anticoagulants. Coumarins only take effect after a few days, while direct oral anticoagulants take effect after just a few hours.
Once a person has got over a pulmonary embolism, doctors usually recommend ongoing treatment with an anticoagulant in order to prevent further thromboses.
There is more information on what anticoagulants are, and what people need to watch out for, on gesundheitsinformation.de.
- Deutsche Gesellschaft für Angiologie – Gesellschaft für Gefäßmedizin e.V. Sk2-Leitlinie. Diagnostik und Therapie der Venenthrombose und der Lungenembolie. Pocket-Version. AWMF-Registernummer 065/002. 2017.
- UpToDate (Internet). Treatment, prognosis, and follow-up of acute pulmonary embolism in adults. Wolters Kluwer 2020. Aufgerufen am 10.02.2021.
- Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. London: National Institute for Health and Care Excellence (UK); 2020 Mar 26. PMID: 32374563.
In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG). As at: