Pulmonary Embolism, abbreviated as PE, refers to a blood clot in the lungs due to obstructions in the pulmonary arteries. The pulmonary arteries extend from the right side of the heart to the lungs and transport deoxygenated blood from the right ventricle into the pulmonary chambers. Here, the exchange of gases occurs wherein blood gets rid of carbon dioxide to be exhaled out of the body through the lungs and refuels with oxygen to be delivered to cells and tissues in the system.

Most instances of pulmonary embolism are triggered by blood clots that move up to the lungs from deep veins in the legs – a condition known as deep vein thrombosis. A pulmonary embolism blocks airways in the lungs and is hence a life-threatening disorder that requires immediate medical treatment to avert grave health complications and death.

Also Read: Deep Vein Thrombosis: Causes, Symptoms And Treatment
Pulmonary Embolism

Causes Of Pulmonary Embolism:

Pulmonary embolisms occur primarily owing to solid masses – blood clots – getting trapped in the tubular pathways of the pulmonary arteries – the blood vessels leading up to the lungs form the heart. The chief reason for this is blood clots confined in the interior portions of the legs, an ailment called deep vein thrombosis (DVT). As a result, the segment of the lungs receiving blood from the blocked pulmonary artery undergo damage and deterioration due to lack of steady blood supply and eventually die – a disorder called pulmonary infarction.

Sometimes, the obstructions in the pulmonary arteries that prompt a pulmonary embolism arise from components other than blood clots. These consist of wedged air bubbles, parts of a tumour growth or even fat deposits that detach from long broken bones and reach the pulmonary arteries leading up to the lungs.

Risk Factors:

Several attributes predispose an individual to blood clots in the legs and other parts of the body and thereby to develop a pulmonary embolism, such as:

  • Habitual smoking of tobacco
  • Excessive body mass, like being overweight or suffering from obesity
  • Pregnancy
  • Intake of estrogen supplements by means of birth control pills or while undergoing hormone replacement therapy
  • Prolonged bed rest
  • Extended periods of travel in a car, bus, train or plane while remaining seated in the same position
  • Pre-existing heart problems like cardiovascular disease (CVD)
  • Cancerous conditions such as lung cancer, kidney cancer, colon cancer
  • Having undergone surgery recently for other underlying ailments
  • Inherited clotting disorders like thrombosis
  • Contracting COVID-19, the infectious viral disease of the upper respiratory tract that hampers lung functions

Also Read: Lung Cancer: Causes, Symptoms And Treatment


The symptoms of pulmonary embolism differ among affected individuals based on the extent of lung damage, size of the blood clots within the pulmonary arteries and pre-existing comorbidities of lung ailments or heart disease. The characteristic indications of pulmonary embolisms comprise:

  • Shortness of breath
  • Chest pain
  • Incessant coughing, with discharge of blood or sputum
  • Irregular heartbeat i.e. arrhythmia
  • Feeling faint and dizzy
  • Sweating profusely
  • Fever
  • Pain and swelling in the legs, particularly in the calf muscles, from DVT
  • Unusual blue discolouration in the skin i.e. cyanosis


The doctor records the medical history of the patient first, to note if they already suffer from lung or heart disease and conduct a thorough physical exam to check the vitals such as rate of heartbeat, pulse, breathing.

A specialized blood analysis known as D-dimer test is carried out, to probe for blood clots in the system and a chest X-ray is taken, to obtain detailed images of the interior chambers of the heart and lungs to identify any abnormal lumps or clots.

Additional visual probes of CT scan, MRI scan and ultrasound are conducted to obtain cross-sectional images of the lungs and pulmonary arteries.

Also Read: Magnetic Resonance Imaging/MRI Scan: Procedure, Risks And Results

Invasive testes including ventilation perfusion scan and pulmonary angiogram are also conducted, to analyse the blood flow within the pulmonary arteries and the lungs.


As soon as the diagnosis of pulmonary embolism is confirmed, the patient must be given prompt medical treatment to prevent serious consequences of lung failure and death.

Treatment for pulmonary embolism entails prescription medications such as blood thinners known as anticoagulants and clot dissolvers i.e. thrombolytics. These potent medicines avert further blood clots from blocking the pulmonary arteries and help diminish the existing clots in the airways.

In cases where the blood clots in the lungs are very large in size, then the physician advises the patient to undergo surgery, to remove the clot, by inserting a thin flexible tube known as a catheter via the blood vessels.

Once immediate medical treatment has been provided, the healthcare professional continues to monitor the vital signs of the patient, to prevent recurrence of pulmonary embolisms and avert serious impairment of the lungs and heart. This helps alleviate symptoms of breathing difficulty and chest pain in the patient and aids in their full recovery.