Which of the following is listed as a cause of hemoptysis?

• A. Pulmonary infarction
• B. Pneumonia
• C. Bronchitis
• D. Trauma

Answer: (A)

Hemoptysis happens when bleeding enters the airways from the lungs. A pulmonary infarction—typically from a pulmonary embolism blocking blood flow to a portion of the lung—causes ischemic damage and rupture of small vessels, leading to bleeding into the airways and coughing up blood. This mechanism makes infarction a classic listed cause of hemoptysis.

Pneumonia and bronchitis involve infection and inflammation of the airways and lung tissue and can produce sputum that’s bloody on occasion, but they are less often cited as direct, primary causes of hemoptysis in standard references. Trauma can cause bleeding as well, but the scenario most often highlighted as a recognized cause in exam contexts is infarction from embolic obstruction.