What are the symptoms of pulmonary embolism?

A pulmonary embolism happens when a clot blocks blood flow in the lungs. Breathlessness may begin suddenly and can occur at rest or with activity. Chest pain is often sharp and may worsen with a deep breath or cough. Other possible signs include a racing heartbeat, light-headedness, fainting, anxiety, sweating or coughing up blood. Some people also have pain or swelling in one leg, although this is not always present.

Treat sudden unexplained breathlessness or chest pain as urgent. Stop exertion, sit upright if that helps you breathe, and seek emergency medical help. Do not drive yourself if you are faint, very breathless or confused. A clinician will assess the symptoms and decide which tests and treatment are needed; anticoagulation management may be part of care after diagnosis.

Call emergency services immediately for severe or sudden breathing difficulty, chest pain, coughing up blood, fainting, blue lips, confusion or a very fast heartbeat. A pulmonary embolism can become life-threatening quickly, so do not wait to see whether symptoms settle.

Ask what may explain your symptoms, which warning signs need emergency action, whether your medicines affect clotting, and how anticoagulation should be monitored if treatment is prescribed.