What is the most common cause of obstructive shock?

The most common cause of obstructive shock is pulmonary embolism (PE). In this condition, a blood clot travels to the pulmonary arteries, obstructing blood flow to the lungs and preventing proper gas exchange. This obstruction leads to a significant decrease in cardiac output, as the right ventricle struggles to pump blood against the blockage. As a result, the body's tissues become inadequately perfused, leading to symptoms associated with shock.

While other conditions such as cardiac tamponade and tension pneumothorax may also cause obstructive shock, pulmonary embolism is particularly common due to the prevalence of venous thromboembolism events in the general population, especially among high-risk groups. Myocardial infarction, on the other hand, is a primary cause of cardiogenic shock rather than obstructive shock.