Pulmonary embolism is a blockage in a blood vessel in the lungs caused by a blood clot that's travelled from another part of the body, such as a leg.
Doctors call blood clots in a vein venous thrombosis. Pulmonary embolism, or PE, is a type of venous thromboembolism, also known as VTE.
Pulmonary embolism is a medical emergency and can be life-threatening, although the symptoms may not be clear, or there may be no symptoms at all.
Around three to four people per 10,000 are diagnosed with a pulmonary embolism in the UK each year, although the NHS says the actual number of cases is probably higher.
Pulmonary embolism symptoms
Pulmonary embolism may not cause symptoms, and if there are symptoms, they may suggest other health problems. However, symptoms which may suggest pulmonary embolism include:
- Sudden coughing, coughing-up blood
- Sharp stabbing chest pain
- Rapid breathing or shortness of breath
- Severe light-headedness, passing out, feeling faint or dizzy
If you think you have pulmonary embolism, seek urgent medical advice, call 999 or go to an accident and emergency department (A&amp;E) immediately.
Pulmonary embolism causes
Pulmonary embolism is associated with DVT ( deep vein thrombosis). The main cause of DVT is poor blood flow, which can be as a result of sitting still for too long, for example on a long distance flight. When circulation slows down, blood may pool and form clots.
Other DVT risks include pregnancy, cancer, heart failure, damage to blood vessel walls or having a hip, knee or abdomen operation (surgery).
Pulmonary embolism risks increase in people aged over 40, smokers, those with have a family history of blood clots or who are overweight or obese.
Using contraceptive pills or hormone-replacement therapy (HRT) is also linked with pulmonary embolism.
Pulmonary embolism diagnosis
Symptoms alone do not help doctors with an accurate way to diagnose pulmonary embolism. Tests may include:
- Lung tests, ventilation or perfusion scan to measure air in the lungs and blood flow in the lungs
- Chest X-ray
- VQ CAT scan
- D-dimer test that detects a protein released by blood clotting
- Computed tomography pulmonary angiography (CTPA) using dye to give a clearer scan of the lungs
Pulmonary embolism treatment
The NHS says around half of all cases of pulmonary embolism happen in hospital, where diagnosis and treatment can be carried out quickly.
The goal of treatment is to dissolve any existing clots safely, called thrombolytic therapy, and to stop new clots building-up.
Clot prevention involves taking anticoagulant medicines such as heparin and warfarin. Regular INR blood tests are needed to make sure the right anticoagulant dose is being given to prevent dangerous clots, but not put the patient in danger of excessive bleeding.
Prevention of pulmonary embolism
Once diagnosed with pulmonary embolism, anticoagulant medicines will be given to help prevent further clots.
One of the ways to prevent pulmonary embolism is reducing risk factors for DVT.
- Taking regular exercise, at least 150 minutes a week
- Maintaining a healthy weight and diet
- Quitting smoking
- Getting blood pressure checked regularly and keeping it well managed
- Discussing with your doctor alternatives to contraceptive pills or hormone-replacement therapy (HRT)
- Wearing compression stockings if advised to do so
- Keep mobile on long plane journeys