What is a pulmonary embolism?

• A. Air bubble in the lungs
• B. Blood clot in the lungs
• C. Infection in the lungs
• D. Fluid in the lungs

Answer: (B)

Pulmonary embolism is a blockage of the pulmonary arteries in the lungs, most commonly caused by a blood clot that has traveled from a deep vein in the leg or pelvis to the lungs. This is why a blood clot in the lungs is the best description for the correct answer. An air bubble in the lungs would be an air embolism, a different mechanism. An infection in the lungs is pneumonia, not an embolic blockage. Fluid in the lungs indicates edema or effusion, again not an embolus. In real clinical terms, a PE often causes sudden shortness of breath and chest pain and is diagnosed with imaging like CT pulmonary angiography and treated with anticoagulation.