What is the result of a severe pneumothorax?

A severe pneumothorax occurs when air enters the pleural cavity, the space between the lungs and the chest wall. In this condition, the presence of air disrupts the negative pressure that typically exists in the pleural cavity, which is essential for keeping the lungs inflated. This negative pressure allows the lungs to expand and contract properly during respiration. When a severe pneumothorax occurs, the air in the pleural space causes a collapse of the affected lung, leading to reduced lung function and difficulty breathing.

The disruption of the negative pressure in the pleural cavity effectively means the lungs can no longer expand fully. This results in significant respiratory distress and can be life-threatening if not treated promptly. Understanding this mechanism highlights the importance of maintaining normal pleural physiology for optimal respiratory function.