Pulmonary Embolism



A PE is often caused by a blood clot in the leg or pelvis that travels to the lungs. Less common causes include floating pieces of fat, tumor tissue, or air.

Risk Factors

Having a blood clot in a deep vein of a leg or the pelvis raises the risk of PE. Other things that may raise the risk are:

  • Lack of activity due to things like bed rest or a long trip
  • Blood clotting disorders
  • Recent surgery
  • Bone fractures
  • Cancer and cancer treatment
  • Being overweight or obese
  • Smoking
  • Recent pregnancy or childbirth
  • Some medicines, such as birth control pills and hormone replacement therapy
  • Health problems such as stroke, heart disease, and high blood pressure



The symptoms of PE will depend on the size and location of the blockage. The amount of lung tissue that has reduced blood flow will also affect the symptoms. PE may cause:

  • Problems breathing, such as shortness of breath and fast breathing
  • Chest pain
  • Cough, sometimes with bloody phlegm
  • Fever
  • Feeling faint or lightheaded
  • Seizures


The doctor will ask about symptoms and past health. A physical exam will be done.

Blood tests will be done to look for signs of a clot and to check oxygen levels.

Images may be taken. This may be done with:

  • Chest x-ray
  • CT scan
  • Lung ventilation and perfusion scan
  • Pulmonary angiogram
  • Ultrasound
  • MR angiogram
  • Echocardiogram

An electrocardiogram (EKG) may be done to check the electrical activity of the heart.



Treatment depends on the size of the clot and the symptoms it is causing. Emergency treatment may be needed.


Medicine may be given to break up the clot. Blood thinners may be used to make it harder for new clots to form.


Some people may need surgery when medicine does not break up the clot or the clot is very large.

Clot-trapping Filter

A filter may be needed in people who are not helped by other methods. It will be placed inside a large vein in the belly. The filter will catch blood clots that leave the lower body and trap them before they reach the lungs.


To lower the risk of blood clots that cause PE:

  • Break up long periods of sitting. Get up and walk every few hours.
  • People who have had a recent illness or surgery should begin to walk as soon as it is safe to do so.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.