**Abstract**

Pulmonary embolism is an acute emergency due to the occlusion of the pulmonary arteries by a venous blood clot. The pathophysiology of pulmonary embolism follows Virchow's triad, which encompasses stasis in veins, increased coagulation, and vessel wall trauma. Pregnancy, major trauma or surgery, prolonged immobilization, obesity, medication, and inherited risks are important risks. It is an essential rule-out diagnosis in chest pain and dyspnea patients in the emergency room. It is also responsible for significant mortality if not diagnosed and treated promptly. Physicians utilize multiple algorithmic scores and calculators to supplement diagnosis along with a high degree of clinical suspicion at initial presentation. Clinical diagnosis involves utilizing multiple modalities, including D-dimer, troponin, arterial blood gas analysis, electrocardiogram, bedside echocardiogram, and imaging modalities such as venous duplex, chest computed tomography, ventilation-perfusion scans, and pulmonary angiogram. Some imaging modalities carry the risk of radiation and being invasive. The treatment can itself be short-term or lifelong based on the causative factor. Anticoagulants used in the therapy can itself cause devastating complications if not monitored appropriately. Despite adequate treatment, some of these patients progress to chronic disease resulting in secondary pulmonary hypertension.

**Keywords:** Pulmonary embolism, diagnosis, computed tomography, risk factors
