What is a pulmonary embolism?

A pulmonary embolism is a blood clot in the lung that occurs when a clot in another part of the body (often the leg or arm) moves through the bloodstream and becomes lodged in the blood vessels of the lung. This restricts blood flow to the lungs, lowers oxygen levels in the lungs and increases blood pressure in the pulmonary arteries.

If a clot develops in a vein and it stays there, it’s called a thrombus. If the clot detaches from the wall of the vein and travels to another part of your body, it’s called an embolus.

If PEs are not treated quickly, they can cause heart or lung damage and even death.

Who is at risk of developing a blood clot?

People at risk for developing a blood clot are those who:

  • Have been inactive or immobile for long periods of time due to bed rest or surgery.
  • Have a personal or family history of a blood clotting disorder, such as deep vein thrombosis (DVT) or pulmonary embolism (PE).
  • Have a history of cancer or are receiving chemotherapy.
  • Sit for prolonged periods.

People at risk for developing a pulmonary embolism include those who:

  • Are inactive for long periods of time while traveling via motor vehicle, train or plane.
  • Have a history of heart failure or stroke.
  • Are overweight or obese.
  • Have recently had trauma or injury to a vein, possibly after a recent surgery, fracture or due to varicose veins.
  • Are pregnant or have given birth in the previous 6 weeks.
  • Are taking birth control pills (oral contraceptives) or hormone replacement therapy.
  • Placement of central venous catheters through the arm or leg If you have any of these risk factors and you have had a blood clot, please talk with your health care provider so steps can be taken to reduce your personal risk.

How serious is a pulmonary embolism?

A pulmonary embolism may dissolve on its own; it is seldom fatal when diagnosed and treated properly. However, if left untreated, it can be serious, leading to other medical complications, including death. A pulmonary embolism can:

  • Cause heart damage.
  • Be life-threatening, depending on the size of the clot.

What are the symptoms of pulmonary embolism?

Symptoms of pulmonary embolism vary, depending on the severity of the clot. Although most people with a pulmonary embolism experience symptoms, some will not. The first signs are usually shortness of breath and chest pains that get worse if you exert yourself. You may cough up bloody sputum. If you have these symptoms get medical attention right away. Pulmonary embolism is serious but very treatable. Quick treatment greatly reduces the chance of death.

Symptoms may include:

  • Sudden shortness of breath -- whether you’ve been active or at rest.
  • Unexplained sharp pain in your chest, arm, shoulder, neck or jaw. The pain may also be similar to symptoms of a heart attack.
  • Cough with or without bloody sputum (mucus).
  • Pale, clammy or bluish-colored skin.
  • Rapid heartbeat (pulse).
  • Excessive sweating.
  • In some cases, feeling anxious, light-headed, faint or passing out.
  • Wheezing.

It is also possible to have a blood clot and not have any symptoms, so discuss your risk factors with your health care provider.

If you have any symptoms of pulmonary embolism, get medical attention immediately.

What causes pulmonary embolism?

Pulmonary embolism may occur:

  • When blood collects (or “pools”) in a certain part of the body (usually an arm or leg). Pooling of blood usually occurs after long periods of inactivity, such as after surgery or bed rest.
  • When veins have been injured, such as from a fracture or surgery (especially in the pelvis, hip, knee or leg).
  • As a result of another medical condition, such as cardiovascular disease (including congestive heart failure, atrial fibrillation and heart attack) or stroke.
  • When clotting factors in the blood are increased, elevated, or in some cases, lowered. Elevated clotting factors can occur with some types of cancer or in some women taking hormone replacement therapy or birth control pills. Abnormal or low clotting factors may also occur as a result of hereditary conditions.

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