Pulmonary embolism (PE): explained in layman's terms

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23 aug 2025

Pulmonary embolism (PE): explained in human language

 

What is this disease?

PE is a situation when the pulmonary artery is suddenly “closed” by a thrombus, that is, a blood clot. Because of this, blood cannot flow freely to the lungs, and the body immediately experiences a lack of oxygen. This condition is very dangerous and without timely assistance can have serious consequences.
Most often, the “culprits” are blood clots that first formed in the deep veins of the legs or pelvis, and then broke off and “traveled” to the lungs.
Why does this happen?

There can be many reasons, but they can be conditionally divided into two groups:

What triggers the formation of blood clots: inactivity, prolonged lying after operations or injuries, excess weight, hormonal drugs, pregnancy, varicose veins or other problems with the veins.
What helps them break off: heavy lifting, injuries, even a long flight.
In rare cases, the cause may not be the blood clots themselves, but fat droplets, tumor cells or air bubbles, which can also “block the road” in the vessel.

 

How does the patient feel?

When a clot has closed the vessel, symptoms appear almost instantly. The most typical are:

• sudden shortness of breath - as if the air has become half as small;
• chest pain - stabbing or squeezing;
• the heart beats rapidly, sometimes “beats out of rhythm”;
• weakness, dizziness appear;
• the skin and lips may turn blue due to lack of oxygen;
• dizziness, sometimes loss of consciousness;
• sometimes - a cough with blood.
• Even one such symptom, especially if it occurs unexpectedly, is a good reason to immediately call an ambulance.

 

  

 

What are the forms?

• Instantaneous (massive) - blockage of a large vessel, life-threatening in the first minutes.
• Acute - symptoms develop over a few hours.
• Subacute - develops gradually, over weeks, and is often misleading.
• Chronic - when small blood clots appear from time to time, gradually worsening the function of the heart and lungs.

 

Diagnosis: what do doctors do?

To confirm the diagnosis, these methods are used:

• blood test for D-dimer (indicates the presence of blood clots, but does not confirm 100%);
• Ultrasound of the veins of the legs and pelvis - to find the source;
• CT angiography of the lungs - the "gold standard" for detecting a blood clot;
• CT of the veins of the pelvis and inferior vena cava;
• ECG and echocardiography - assessment of the heart and pulmonary artery;
• Blood gas analysis, X-ray to assess the general condition.

 

What to do before the doctor arrives?

• Call emergency services (103).
• provide the person with peace and place them in a semi-sitting position;
• unbutton their clothes, open the window for air access;
• prohibit any physical exertion so as not to provoke a second embolism
• do not give water or medication without the permission of a doctor;
• make sure that the person does not lose consciousness and does not stop breathing;
• in case of respiratory or cardiac arrest - start basic cardiopulmonary resuscitation (CPR)
• if the patient is already taking anticoagulants (warfarin, apixaban, rivaroxaban, dabigatran, enoxaparin) - you can give another dose, but do not start a new therapy yourself until the doctor arrives.
• Nitroglycerin or painkillers - do not give without indications.

⚠️ The most important thing is to urgently call an ambulance and keep the patient calm, because PE treatment is possible only in a hospital setting (thrombolysis, anticoagulation, oxygen therapy, sometimes - catheter or surgical methods).

 

How is PE treated in the hospital?

• Oxygen support - to saturate the blood with oxygen.
• Blood thinners - anticoagulants.
• Thrombolytics - dissolve the clot (in severe cases, namely massive PE).
• Surgical removal of the blood clot or installation of a special cava filter in the vein to intercept new blood clots
• Endovascular or surgical methods: catheter thrombectomy or local thrombolysis
• Supportive treatment: pain relief, blood pressure control, treatment of heart failure and complications.
• After the acute phase, long-term treatment and monitoring are required to prevent recurrence.

 

 

 

How to prevent PE?

• move regularly, even if the job is sedentary;
• use compression hosiery if prone to thrombosis;
• control weight, blood pressure, quit smoking;
• do leg exercises and drink enough water when traveling;
• after operations or injuries — follow the doctor’s recommendations for the prevention of blood clots.
• Regularly undergo check-ups with a phlebologist or vascular surgeon with ultrasound of the veins.

 

Conclusion
PE is a serious and potentially fatal complication. But at the same time, it is a condition that can be recognized in time and effectively treated.

The main rule: any sudden shortness of breath or chest pain — do not wait, but act immediately. If you suspect PE, you should immediately call an ambulance, because treatment is possible only in a hospital and includes anticoagulants, oxygen, and in severe cases, dissolving or removing the blood clot. Early treatment to a doctor significantly increases the chances of recovery and prevents complications.

Author: Simonenko Maxim MD ©