Which of the following is a specific risk factor for pulmonary embolism?

Recent hip surgery is a specific risk factor for pulmonary embolism because surgical procedures, especially those involving the lower extremities, can lead to immobility and the formation of blood clots in the deep veins of the legs (deep vein thrombosis or DVT). When a clot dislodges, it can travel to the lungs, resulting in a pulmonary embolism. Post-operative patients are at an elevated risk due to factors such as reduced mobility, blood vessel injury during surgery, and changes in blood coagulability.

While obesity, a history of smoking, and other factors can contribute to the overall risk of developing clots and pulmonary issues, they are more general risk factors. The link between recent hip surgery and pulmonary embolism is direct and is often addressed in medical protocols and preventive measures offered to patients undergoing such procedures, underscoring the importance of vigilant post-operative care.