A pulmonary embolism is a clot blocking a blood vessel to the lungs. This threatens to stop you breathing in oxygen to keep organs alive, and stops you getting rid of toxic carbon dioxide gas. This can be life-threatening and requires immediate hospital admission. With prompt recognition and treatment, most people recover from PEs.
You will likely have sudden pain in the chest or upper back. You will be taking fast shallow breaths, your heart will be racing and you will feel faint or unwell. You may notice blood if you cough anything up. To bystanders, you may look pale and unwell, or you could have collapsed. You – or hopefully someone with you – should call for an ambulance with these symptoms, or get to your nearest Emergency Department immediately. If you have a milder version than this, and you have risk factors below, see your doctor urgently or attend your Emergency Department for an assessment.
Most often, you will have developed a clot in a blood vessel in your leg, called a deep vein thrombosis (DVT). You will notice this as a red, hard, sore area on one of your calves, and that calf will be more swollen than the other one. Part of a clot breaks off from the DVT and travels to the lungs to cause a PE. Periods of inactivity or immobility can cause this – long operations on your legs or pelvis in the previous four weeks, or broken bones or illness that have laid you in bed for more than three days. COVID-19 puts people at a higher risk of PEs – those who have had most severe illness, usually requiring intensive care admission, are most at risk. A hospital team will assess your risk of clotting versus bleeding, and will usually give an anticoagulant injection while you remain immobile, to prevent clots. A diagnosis of cancer, with current treatment or treatment within the last six months, can put you at higher risk. Pregnancy is another risk factor, and for six weeks after delivery. Other factors may contribute, such as dehydration, flights or travel for more than six hours or certain clotting disorders of the blood. Making sure you stay well-hydrated and mobile where able will help. For long-haul flights, it’s not recommended you take aspirin, unless you are prescribed this for another reason, but you should move around and stretch your legs, and you may wish to buy compression stockings – your pharmacist should be able to help you get the right size.
The medical team will assess you. They will take your vital signs: your heart rate and breathing rate will be raised, and your blood pressure may be low. They will consider other causes for your symptoms and provide any life support you need. If they strongly suspect a PE and you are very unwell, they will start treatment before waiting for further investigations. They will likely do a scan of your chest called a CTPA, and they may perform a blood test looking for a particular marker called a D-dimer.
Anticoagulants work to break down any blood clot. You will likely have these as heparin injections for the first five days or so. They will be replaced with anticoagulant tablets for you to take at home, and treatment usually continues for at least three months. Your medical team will consider likely causes and try to minimise risks to avoid a DVT or PE in future.