A pulmonary embolism is a blockage of an artery in the lungs. The embolism prevents blood and nourishment from getting to a specific area of the lungs. This may lead to the death of lung tissue in this area. Damage to the lungs may make it difficult for the lungs to work properly. In severe cases, a pulmonary embolism can lead to death.
Pathway of Pulmonary Embolism
Copyright © Nucleus Medical Media, Inc.
An embolism is caused by a lump of material, called an embolus, that is floating in the blood. An embolus can be a blood clot, air bubble, a piece of fat, bone marrow, or tumor tissue. The embolus travels from its original location and passes through larger blood vessels until it gets stuck in a smaller blood vessel. In this case, the embolus is trapped in an artery of the lungs.
The embolus in a
is usually a blood clot. It most often starts in a vein in the legs or pelvis.
Factors that may increase your chance of a pulmonary embolism include:
The symptoms of a pulmonary embolism vary depending on the size and location of the blockage. The area of lung affected by the lack of blood will also affect the symptoms. Pulmonary embolism may cause:
- Shortness of breath that starts suddenly for no obvious reason
Chest pain, especially when breathing or coughing (it can mimic a
- Feeling faint or lightheaded
- Cough, sometimes with bloody phlegm
- Rapid heartbeat
- Rapid breathing
- Feeling of impending doom
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may order the following tests:
- Arterial blood gas study—to check oxygen levels and lung function
- Electrocardiogram (EKG)—to assess the electrical activity of the heart
- D-Dimer blood test—to detect the presence of a clot
If you have a family history of blood clots, and had blood clots in the past for no apparent reason, your doctor may do additional blood tests. The tests will look for possible inherited defects in your clotting system, such as:
- Factor V Leiden mutation (seen in up to 40% of cases)
- Increased factor VIII
Imaging tests evaluate the lungs and surrounding structures. These may include:
Treatment depends on the size and severity of the clot. Emergency treatment and hospitalization may be needed.
Emergency treatment for shock may include IV fluids, medications, and oxygen therapy.
Treatment includes medication, and in some cases, surgery.
Medications are used to break up and control the clot. After the initial period, the blood thinner will be switched to a longer-acting anticoagulants.
Another type of medication may be needed to dissolve the clot. These are called thrombolytics. This type of medication is usually only used in people with a pulmonary embolism that is very large or is causing severe illness. Thrombolytics will not be used if you have a high risk of bleeding.
Surgery to remove the clot may be needed if the blockage is very large, not responding to treatment, or the person is in shock. The surgery is called an embolectomy.
Some people may have repeated problems with blood clots. Others cannot take anticoagulant medications. In these cases, a surgical procedure will be done to place a filter in the main veins of the legs. The filter will trap clots before they can travel to the lungs.
To reduce your chance of a pulmonary embolism:
that is low in saturated fat and rich in whole grains, fruits, and vegetables.
Begin a safe
with the advice of your doctor.
- Walk or move your legs to break up long periods of sitting.
If you smoke, talk with your doctor on ways you can
- Unless you are on a fluid-restricted diet, be sure to drink lots of water.
People at high risk of developing blood clots can do the following:
- Take medication if your doctor recommends it. Anticoagulant drugs are most commonly used.
- Wear elastic stockings if suggested by your doctor. They can help improve circulation in your legs.
- Walk or move your legs to break up long periods of sitting. If you are traveling, get up and walk every few hours.
Gibson NS, Sohne M, etc. Prognostic value of echocardiography and spiral computed tomography in patients with pulmonary embolism.
Curr Opin Pulm Med.
Guyatt GH, Norris SL, et al; American College of Chest Physicians. Methodology for the development of antithrombotic therapy and prevention of thrombosis guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
Chest. 2012 Feb;141(2 Suppl):53S-70S.
Konstantinides S. Clinical practice. Acute pulmonary embolism.
N Engl J Med.
Philbrick JT, Shumate R, et al. Air travel and venous thromboembolism: a systematic review.
J Gen Intern Med. 2007;22:107-114.
JAMA. February 2001.
EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated September 11, 2014. Accessed September 26, 2014.
Pulmonary embolus. The Lung Association website. Available at:
http://www.lung.ca/diseases-maladies/a-z/embolus-embolie/index_e.php. Updated September 24, 2012. Accessed August 28, 2013.
Qaseem A, Snow V, et al. Current diagnosis of venous thromboembolism in primary care: a clinical practice guideline from the American Academy of Family Physicians and the American College of Physicians.
Ann Intern Med. 2007;146:454-458.
Rubini G, Niccoli A, et al. Acute pulmonary embolism: comparison and integration of perfusion lung scintigraphy with multislice spiral CT.
Radiol Med. 2007;112:174-184.
10/5/2010 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: Parker C, Coupland C, Hippisley-Cox J. Antipsychotic drugs and risk of venous thromboembolism: nested case-control study.
DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: Grainge MJ, West J, Card TR.
Venous thromboembolism during active disease and remission in inflammatory bowel disease: a cohort study.
DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed: Zöller B, Li X, Sundquist J, Sundquist K. Risk of pulmonary embolism in patients with autoimmune disorders: a nationwide follow-up study from Sweden.
Last reviewed August 2014 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.