Pulmonary Embolism

A pulmonary embolism is a blockage of an artery in the lungs, usually caused by a blood clot that has travelled from a deep vein, most often in the leg. It is a life-threatening emergency requiring immediate treatment.

• Sudden shortness of breath, at rest or on exertion
• Sharp chest pain that often worsens with breathing in
• Rapid heart rate
• Coughing, sometimes with blood-streaked sputum
• Lightheadedness, fainting, or signs of shock in more severe cases
• Symptoms often occur alongside or shortly after signs of deep vein thrombosis, such as leg swelling

• Most commonly results from a blood clot that has formed in a deep vein (deep vein thrombosis), usually in the leg, breaking off and travelling to the lungs.
• Risk is increased by prolonged immobility, recent surgery, pregnancy and the postpartum period, cancer, oestrogen-containing contraception, obesity, and inherited or acquired clotting disorders.

• Diagnosed using a structured clinical risk assessment together with imaging, most definitively a CT pulmonary angiogram where available.
• D-dimer blood testing may support the diagnosis in lower-risk cases, though it is not specific on its own.
• Pulse oximetry often shows reduced blood oxygen, and an ECG may show changes suggestive of strain on the heart's right side, though these are supportive rather than definitive findings.

Pulmonary embolism is a medical emergency requiring immediate hospital assessment and treatment.

Anticoagulant (blood-thinning) medicine is started promptly once the diagnosis is confirmed or strongly suspected, to prevent further clot growth and reduce the risk of another embolism, typically continued for at least three months depending on the underlying cause.

Patients with signs of severe strain on the heart or significant shock may require more intensive treatment, including clot-dissolving medicine, at a facility capable of this level of care.

Oxygen therapy is given for low blood oxygen, and close monitoring is essential given the risk of rapid deterioration.

• Stay mobile and move the legs regularly during long journeys or periods of bed rest.
• Use preventive anticoagulant medicine or compression devices as prescribed after major surgery, when at high risk.
• Seek prompt medical assessment for unexplained leg swelling or pain, since untreated deep vein thrombosis can lead to pulmonary embolism.
• Seek immediate emergency care for sudden breathlessness or chest pain, particularly with risk factors present.