What is the most common cause of pulmonary embolism?

The most common cause of pulmonary embolism is deep vein thrombosis (DVT). DVT refers to the formation of blood clots in the deep veins, primarily in the legs. When a DVT occurs, these clots can dislodge and travel through the bloodstream to the pulmonary arteries, leading to a pulmonary embolism. The circumstances that contribute to DVT include prolonged immobility, recent surgeries, certain medical conditions, and risk factors such as obesity, smoking, and hormonal therapies.

Understanding the relationship between DVT and pulmonary embolism is crucial, as it emphasizes the importance of early identification and prevention of venous thromboembolism in at-risk patients. The other causes, while significant in certain contexts, do not represent the most prevalent source of pulmonary embolism. For instance, fat emboli typically occur after trauma or surgery involving long bones, and air emboli are much less common, primarily arising from procedures like central line placement. Pulmonary hypertension is a serious condition but is usually a result of other underlying issues rather than a direct cause of pulmonary embolisms.