Blockage of a pulmonary artery due to a blood clot or other obstruction is known as which condition?

• A. Pneumothorax
• B. Aortic dissection
• C. Pulmonary embolism
• D. Pulmonary edema

Answer: (C)

A blockage of a pulmonary artery by a clot or other obstruction is called a pulmonary embolism. It happens when a thrombus, often from the legs, travels to the lungs and lodges in a pulmonary artery, stopping blood flow to part of the lung. This creates a mismatch between air reaching the lungs and blood flow, leading to low oxygen levels and potential strain on the right side of the heart, especially in larger clots. Clinically, it often presents with sudden shortness of breath and chest pain. This differs from a pneumothorax, which is air in the pleural space causing lung collapse; an aortic dissection, which is a tear in the aorta; and pulmonary edema, which is fluid buildup in the lungs from heart failure.