What causes an pulmonary embolism?

Pulmonary embolism (PE) occurs when a blood clot (thrombus) forms in a large vein, usually in the legs or pelvis, and travels through the bloodstream to the lungs. This can block blood flow to the lungs and cause serious medical problems.

The most common cause of PE is deep vein thrombosis (DVT), which is the formation of a blood clot in a deep vein, usually in the leg. DVT can occur for a number of reasons, including:

* Prolonged sitting or lying down: This can slow down blood flow and increase the risk of blood clots forming.

* Obesity: Obesity can increase the risk of blood clots by putting pressure on the veins and slowing down blood flow.

* Smoking: Smoking damages the lining of the blood vessels and increases the risk of blood clots forming.

* Birth control pills or hormone replacement therapy: These medications can increase the risk of blood clots by changing the levels of hormones in the body.

* Certain medical conditions: Some medical conditions, such as cancer, heart disease, and diabetes, can increase the risk of blood clots forming.

* Surgery: Surgery can damage the blood vessels and increase the risk of blood clots forming.

Other risk factors for PE include:

* Age over 60

* Family history of PE

* Pregnancy

* Recent trauma or injury

* Varicose veins

* Infection

PE can be a serious medical condition, and it is important to seek medical attention immediately if you think you may be experiencing a PE.