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Pulmonary Embolism - What Increases Your Risk

Having a blood clot in the deep vein of your leg and having a previous pulmonary embolism are the two greatest risk factors for pulmonary embolism.

For more information on risk factors for blood clots in the legs, see the topic Deep Vein Thrombosis.

Recommended Related to Lung Disease/Respiratory Problems

Lung Diseases Overview

Lung diseases are some of the most common medical conditions in the world. Tens of millions of people suffer from lung disease in the U.S. Smoking, infections, and genetics are responsible for most lung diseases. The lungs are part of a complex apparatus, expanding and relaxing thousands of times each day to bring in oxygen and expel carbon dioxide. Lung disease can result from problems in any part of this system.

Read the Lung Diseases Overview article > >

Many things increase your risk for a blood clot. These include:

  • Having slowed blood flow, abnormal clotting, and a blood vessel injury.
  • Age. As people get older (especially older than age 70), they are more likely to develop blood clots.
  • Weight. Being overweight increases the risk for developing clots.
  • Not taking anticoagulant medicine as prescribed, unless your doctor tells you to stop taking it.

Slowed blood flow

When blood does not circulate normally, clots are more likely to develop. Reduced circulation may result from:

  • Long-term bed rest, such as if you are confined to bed after an operation, injury, or serious illness.
  • Traveling and sitting for a long time, especially when traveling long distances by airplane.
  • Leg paralysis. When you use your muscles, the muscles contract, and that squeezes the blood vessels in and around the muscles. The squeezing helps the blood move back toward the heart. Paralysis can reduce circulation because the muscles can't contract.

Abnormal clotting

Some people have blood that clots too easily or too quickly. People with this problem are more likely to form larger clots that can break loose and travel to the lungs. Conditions that may cause increased clotting include:

Injury to the blood vessel wall

Blood is more likely to clot in veins and arteries shortly after they are injured. Injury to a vein can be caused by:

  • Recent surgery that involved the legs, hips, belly, or brain.
  • A tube (catheter) placed in a large vein of the body (central venous catheter).
  • Damage from an injury, such as a broken hip, serious burn, or serious infection.

    This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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