What is the leading cause of pulmonary embolism?

The leading cause of pulmonary embolism is deep venous thrombosis (DVT). DVT occurs when a blood clot forms in a deep vein, usually in the legs. If a portion of this clot dislodges, it can travel through the bloodstream to the lungs, resulting in a pulmonary embolism. This condition can lead to severe complications, including reduced blood flow to the lungs and potential respiratory failure.

In contrast, conditions like cholelithiasis (gallstones), acute bronchitis, and chronic cough do not typically involve the formation of blood clots in the deep veins. Cholelithiasis pertains to issues with the gallbladder and does not relate to clot formation. Acute bronchitis is an inflammatory condition of the airways, and while it may lead to respiratory issues, it does not create the conditions for thrombus formation that lead to pulmonary embolism. Similarly, chronic cough is a symptom rather than a primary condition that would result in blood clots. Understanding the relationship between DVT and pulmonary embolism is crucial in identifying and managing risks associated with venous thromboembolism.