What is the medical term for fluid accumulation around the lung?

• A. Pleural effusion
• B. Pneumothorax
• C. Pulmonary edema
• D. Atelectasis

Answer: (A)

Fluid accumulation around the lung occurs in the pleural space, the thin gap between the lung’s visceral pleura and the chest wall’s parietal pleura. When fluid collects there, the condition is called a pleural effusion. It arises from various causes—heart failure, infections, inflammation, malignancy, or trauma—and can lead to shortness of breath and diminished breath sounds at the lung base. Imaging often shows blunting of the costophrenic angles on a chest X-ray, and ultrasound can detect even small effusions. Fluid analysis after drainage helps determine the type (for example, transudate vs. exudate). This is distinct from a pneumothorax, which is air in the pleural space; from pulmonary edema, which is fluid within the lung tissue/airspaces; and from atelectasis, which is collapse of lung tissue.