Risk Factors of Pulmonary Embolism

Pulmonary embolism (PE) occurs equally in men and women. The risk increases with age. For every 10 years after age 60, the risk of having PE doubles.

Certain inherited conditions, such as factor V Leiden, increase the risk of blood clotting and PE.

Major Risk Factors

Your risk for PE is high if you have deep vein thrombosis (DVT) or a history of DVT. In DVT, blood clots form in the deep veins of the body—most often in the legs. These clots can break free, travel through the bloodstream to the lungs, and block an artery.

Your risk for PE also is high if you've had the condition before.

Other Risk Factors

Other factors also can increase the risk for PE, such as:

• Being bedridden or unable to move around much
• Having surgery or breaking a bone (the risk goes up in the weeks following the surgery or injury)
• Having certain diseases or conditions, such as a stroke, paralysis (an inability to move), chronic heart disease, or high blood pressure
• Smoking

People who have recently been treated for cancer or who have a central venous catheter are more likely to develop DVT, which increases their risk for PE. A central venous catheter is a tube placed in a vein to allow easy access to the bloodstream for medical treatment.

Other risk factors for DVT include sitting for long periods (such as during long car or airplane rides), pregnancy and the 6-week period after pregnancy, and being overweight or obese. Women who take hormone therapy pills or birth control pills also are at increased risk for DVT.

The risk of developing blood clots increases as your number of risk factors increases.

Source: National Heart, Lung, and Blood Institute, National Institutes of Health.