Pneumothorax: How a Collapsed Lung Works

A pneumothorax is a collapsed lung caused by air leaking into the pleural space — the gap between the lung and chest wall. Normally this space contains only a thin fluid layer. When air enters, it pushes on the lung and disrupts the pressure balance that keeps it inflated. Types: - Spontaneous: Occurs without obvious cause, often in tall, thin young men (due to small air blebs on the lung surface that rupture) - Traumatic: From injury — rib fractures, stab wounds, or medical procedures - Tension pneumothorax: The most dangerous — air enters with each breath but cannot escape, progressively compressing the lung and eventually shifting the heart (life-threatening emergency) Symptoms: Sudden sharp chest pain, shortness of breath, reduced breath sounds on the affected side. Treatment ranges from observation (small pneumothorax, air reabsorbs naturally) to needle decompression (tension pneumothorax — emergency insertion of a needle or chest tube to release trapped air). The dramatic movie scene of stabbing someone in the chest with a pen to let them breathe is based on real emergency needle decompression of tension pneumothorax — though in practice it requires a proper needle or catheter, not a pen.