Also known as: Collapsed Lung

Pneumothorax is a collapsed lung caused by air leaking into the chest cavity. There are three main types of air leaks.

  • Pneumomediastinum: Air leaks into the mediastinum, the space in the chest (thoracic) cavity behind the breastbone (sternum) and between the two pleural sacs containing the lungs. 
  • Pneumopericardium: Air leaks into the sac surrounding the heart. 
  • Pulmonary interstitial emphysema (PIE): Air leaks out of and between the alveoli, the tiny air sacs of the lungs.

Air leaks may occur suddenly or develop slowly. The severity of the condition depends on the location of the leak, how quickly the leak occurs and the amount of air leaked.