Which term refers to a collapsed lung without trauma?

• A. Oxygen Therapy
• B. Spontaneous Pneumothorax
• C. Pleural Space
• D. Pulmonary Embolism

Answer: (B)

A collapsed lung without trauma is called spontaneous pneumothorax. This happens when air leaks into the pleural space, the narrow gap between the lung and chest wall. That space normally has negative pressure helping keep the lung expanded; when air enters, the pressure balance is disrupted, the lung can no longer stay fully inflated, and it collapses partly or completely. It can occur without any injury (primary) or in people with underlying lung disease (secondary). Oxygen therapy is often part of management because it helps the air in the pleural space reabsorb faster, but the term that names the condition itself is spontaneous pneumothorax. The other terms refer to different concepts: oxygen therapy is a treatment, the pleural space is just the anatomical space, and a pulmonary embolism is a blood clot in the lung that causes symptoms without causing a collapsed lung.