What symptom is most characteristic of a pulmonary embolism?

• A. Gradual onset cough with fever.
• B. Intermittent leg swelling without dyspnea.
• C. Sudden onset dyspnea and pleuritic chest pain.
• D. Chronic productive cough.

Answer: (C)

Pulmonary embolism abruptly disrupts oxygenation because a clot blocks blood flow in the pulmonary arteries, causing a sudden ventilation–perfusion mismatch and triggering rapid breathing and chest pain. The symptom pattern that fits this most closely is sudden onset shortness of breath accompanied by sharp, pleuritic chest pain that worsens with deep breaths. This reflects both the abrupt impairment in gas exchange and irritation of the pleura from the affected lung tissue.

The other options point to different problems: a gradual cough with fever suggests an infectious process like pneumonia, leg swelling without dyspnea could be a venous issue without implying an acute respiratory event, and a chronic productive cough indicates a long-standing lung condition such as chronic bronchitis.