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Diseases A–Z

Pulmonary embolus

Symptoms | Risk Factors | Treatment | Prevention

Pulmonary embolus is a blockage of an artery in the lungs by fat, air, tumour tissue or a blood clot. Pulmonary embolus is also called pulmonary emboli — the plural of embolus is emboli.

What causes pulmonary embolus?

Pulmonary emboli can be caused by:

  • clots from the venous circulation from the right side of the heart
  • tumours that have invaded the circulatory system
  • other sources such as amniotic fluid, air, fat, bone marrow and foreign substances

Most pulmonary embolus are caused from clots originating in the lower extremities (deep vein thrombosis), and many resolve on their own. In some cases, pulmonary embolism can cause sudden death.

Symptoms of pulmonary embolus

People with pulmonary embolus may have:

  • a cough that begins suddenly, and may produce bloody sputum (mucus): significant amounts of visible blood or lightly blood streaked sputum (phlegm)
  • sudden onset of shortness of breath at rest or with exertion
  • splinting of ribs with breathing (for example, bending over or holding the chest)
  • lightheadedness
  • fainting
  • dizziness
  • sweating
  • anxiety
  • rapid breathing
  • rapid heart rate
  • chest pain:
    • under the breastbone or on one side
    • sharp, stabbing, burning, aching or dull, heavy sensation
    • may be worse at night
    • may radiate to the shoulder, arm, neck, jaw, or other area
    • may be worsened by breathing deeply, coughing, eating, bending or stooping

If you have these symptoms, or if you think you have pulmonary embolus, see your doctor right away. Your symptoms could be caused by pulmonary embolus, or they could be caused by another disease; only a doctor can tell.

Risk factors for pulmonary embolus

The risk factors include:

  • prolonged bed rest or inactivity
  • using oral contraceptives (birth control pills)
  • surgery
  • child birth
  • cancer
  • stroke
  • heart attack
  • heart surgery
  • fractures of the hips or femur

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Treatment for pulmonary embolus

Emergency treatment and hospitalization are necessary. Definitive treatment consists of dissolving the clot by thrombolytic therapy. Anticoagulant therapy is preventive by inhibiting further clot formation.

Thrombolytic therapy (clot-dissolving medication) includes streptokinase, urokinase or TPA. Anticoagulation therapy (clot-preventing medication) consists of heparin by intravenous infusion initially, then oral warfarin (Coumadin), or subcutaneous heparin may be started concurrently (at the same time). Oxygen therapy is required to maintain normal oxygen concentrations until the acute injury to the lungs has resolved.

How can you prevent pulmonary embolus?

Early detection and treatment of deep vein thrombosis (clots of the legs) of patients who are at risk can reduce the risk of pulmonary embolus by early walking and activity after surgery. Other clot-preventive measures include leg exercises and elastic support stockings as appropriate. Subcutaneous heparin therapy (low doses of heparin injected under the skin) may be used for those on prolonged bed rest.

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