Symptoms of pulmonary embolism can be attributed to many other health conditions. If your doctor suspects that you may have had a pulmonary embolism, he or she will evaluate whether you have one or more risk factors for developing this condition. Risk factors include:

• A history of blood clots. If you or a member of your immediate family has had blood clots, you may be at a higher risk for developing clots that could break off and cause a pulmonary embolism.
• Other health conditions, such as heart failure, cancer, or severe infection.
• Recent trauma.
• Recent surgery.
• Placement of a catheter (a thin, flexible tube) in a large vein of your body.
• Serious burns.
• Use of hormone medicines, especially birth control pills or other medicines containing estrogen or containing other hormones that are like estrogen.
• Immobilization, such as during long car trips or airplane flights, or during an illness where you have been unable to move for a long period of time.
• Pregnancy.

Smoking and being very overweight (obese) also may increase a person's risk of developing pulmonary embolism.¹

Even though a person's risk for developing pulmonary embolism may increase with the number of risk factors he or she has, the condition also occurs in people without any known risk factors.