Pneumonia is best described as which of the following?

• A. A heart-related edema
• B. Lung inflammation caused by infection with air sacs filled with pus
• C. Spontaneous pneumothorax
• D. Chronic bronchitis

Answer: (B)

Pneumonia is an infection of the lungs that causes inflammation of the air sacs (alveoli). In response to the infection, these alveoli fill with inflammatory exudate, pus, and fluid, so gas exchange becomes less efficient. This alveolar filling with pus and fluid is the hallmark description of pneumonia. Clinically, you often see fever, a productive cough, and shortness of breath as the body fights the infection and the lungs struggle to oxygenate blood. The other options point to different problems: heart-related edema is fluid buildup from the heart, not an infection of the lung tissue; spontaneous pneumothorax is air leaking into the space around the lung causing collapse; chronic bronchitis is long-term inflammation of the airways with cough and mucus production, not infection of the alveoli.