Pulmonary Embolism

A pulmonary embolism is the sudden blockage of a major artery in your lung, occurring when a blood clot that has developed in another part of your body breaks off and travels to the lungs. Pulmonary embolism is the most common type of cardiovascular disease, after heart attack and stroke.

Overview and Symptoms

Overview and Symptoms

Pulmonary embolism is a life-threatening medical emergency. Symptoms tend to occur suddenly. Call 911 if you develop any of these symptoms:

  • Sudden shortness of breath
  • Sharp chest pain, often made worse with coughing or moving
  • Sudden back pain
  • Cough with or without blood
  • Excessive sweating
  • Rapid pulse or breathing
  • Lightheadedness or passing out
  • Blue lips or nail beds

If you recently had a blood clot in your arm or leg, you may also experience symptoms that include:

  • Swelling in the affected limb
  • Increased warmth in the swollen or painful area of the affected limb
  • Leg pain or tenderness that you may only feel when walking or standing
  • Redness or discoloration of your skin
  • Vein enlargement in the affected limb
Risk Factors
  • Recent surgery, in particular abdominal or orthopaedic surgery
  • Trauma or bone fracture
  • Extended bed rest or sitting for a long time, such as during a long flight or car trip
  • Cancer and some cancer treatments, like chemotherapy
  • Previous atrial fibrillation, heart failure, heart attack or stroke
  • Previous pulmonary embolism
  • Pregnancy and the first six weeks postpartum
  • Smoking
  • Obesity
  • Birth control pills or hormones taken for symptoms of menopause
  • Family history of blood clots
  • Inherited blood disorders that make the blood thick (thrombophilia)
  • Inflammatory bowel disease
  • Auto-immune diseases, such as lupus or antiphospholipid syndrome
  • Having a vein catheter, pacemaker or implantable defibrillator

If you are suspected of having a pulmonary embolism, tests to help with diagnosis may include:

  • Chest X-ray
  • CT scan
  • Echocardiogram
  • Leg vein ultrasound
  • Ventilation Perfusing Lung Scan (VQ Scan)
  • Pulmonary angiography
  • Blood tests


Medications that thin the blood are usually the prescribed treatment for pulmonary embolism. If you have severe symptoms, clot-busting medication, giving through an IV line, can be given to immediately destroy a blood clot.

Surgery to remove the blood clot is usually performed only when other treatments have not worked.

Blood clots in the lung can take months or years to fully resolve after initial treatment. Patients treated for pulmonary embolism may develop pulmonary hypertension — high blood pressure in the heart-to-lung system.