Pulmonary embolism

Pulmonary embolism is when one or more pulmonary arteries in your lungs become blocked. In most cases, pulmonary embolism is caused by blood clots that travel to the lungs from the legs or rarely other parts of the body (deep vein thrombosis, or DVT).

Because pulmonary embolism almost always occurs in conjunction with deep vein thrombosis, some doctors refer to the two conditions together as venous thromboembolism (VTE).

Although anyone can develop deep vein thrombosis and pulmonary embolism, factors such as immobility, cancer and surgery increase your risk.

Pulmonary embolism can be life-threatening, but prompt treatment can greatly reduce the risk of death. Taking measures to prevent blood clots in your legs also can help protect you against pulmonary embolism.

Symptoms Causes Risk factors Complications Prevention

Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots (almost never single) and your overall health — especially the presence or absence of underlying lung disease or heart disease.

Common signs and symptoms include:

  • Shortness of breath. This symptom typically appears suddenly and always gets worse with exertion.
  • Chest pain. You may feel like you're having a heart attack. The pain may become worse when you breathe deeply (pleurisy), cough, eat, bend or stoop. The pain will get worse with exertion but won't go away when you rest.
  • Cough. The cough may produce bloody or blood-streaked sputum.

Other signs and symptoms that can occur with pulmonary embolism include:

  • Leg pain or swelling, or both, usually in the calf
  • Clammy or discolored skin (cyanosis)
  • Excessive sweating
  • Rapid or irregular heartbeat
  • Lightheadedness or dizziness

When to see a doctor

Pulmonary embolism can be life-threatening. Seek immediate medical attention if you experience unexplained shortness of breath, chest pain or a cough that produces bloody sputum.

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