Causes
By Mayo Clinic staffPneumothorax can be caused by a chest injury, underlying lung disease or ruptured air blisters (blebs). Pneumothorax also can occur for no obvious reason.
Chest injuries
Any blunt or penetrating injury to your chest can cause lung collapse. Some injuries may happen during physical assaults or car crashes, while others may inadvertently occur during certain medical procedures. Examples include:
- Knife or gunshot wounds
- Blunt trauma from a blow or car crash
- Deployment of a vehicle's air bag
- Fractured ribs, which may puncture the lung
- Cardiopulmonary resuscitation (CPR)
- The insertion of chest tubes
- Lung biopsies taken via a needle through the chest wall
- Procedures using a scope down the throat and into the lung
Underlying lung diseases
Damaged lung tissue is more likely to collapse. Lung damage can be caused by many types of underlying diseases, including:
- Emphysema
- Tuberculosis
- Pneumonia
- Cystic fibrosis
- Lung cancer
- Pulmonary fibrosis
- Sarcoidosis
Ruptured air blisters
Small air blisters (blebs) can develop on the top of your lung. It's uncertain why these blebs appear on some people's lungs and not others, but they occur more often on the lungs of people who are tall and thin. Blebs themselves do not constitute a disease of the lungs. While most blebs rupture for no apparent reason, they can rupture from changes in air pressure when you're:
- Scuba diving
- Flying
- Mountain climbing at high altitudes
Mechanical ventilation
A severe type of pneumothorax can occur in people who need mechanical assistance to breathe. The action of the ventilator, which pushes and pulls air in and out of the lungs, can create an imbalance of air pressure within the chest. The lung may collapse completely and the heart may be squeezed to the point that it can't work properly. A severe pneumothorax is a medical emergency and can be fatal.
- Light RW, et al. Pneumothorax, chylothorax, hemothorax and fibrothorax. In: Mason RJ, et al. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa.: Saunders Elsevier; 2010. http://www.mdconsult.com/das/book/body/192068760-2/0/1288/0.html. Accessed Jan. 26, 2011.
- Celli BR. Diseases of the diaphragm, chest wall, pleura and mediastinum: The pleura. In: Goldman L, et al. Cecil Medicine. 23rd ed. Philadelphia, Pa.: Saunders Elsevier; 2008. http://www.mdconsult.com/das/book/body/191371208-2/0/1492/0.html#. Accessed Jan. 26, 2011.
- Rosenow EC (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 31, 2011.
- Eckstein M, et al. Thoracic trauma: Pulmonary injuries. In: Marx JA, et al. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2010. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-323-05472-0..X0001-1--TOP&isbn=978-0-323-05472-0&uniqId=230100505-57. Accessed Jan. 26, 2011.
- Legome E. General approach to blunt thoracic trauma in adults. http://www.uptodate.com/home/index.html. Accessed Jan. 26, 2011.
- Light RW. Secondary spontaneous pneumothorax in adults. http://www.uptodate.com/home/index.html. Accessed Jan. 26, 2011.
- Light RW. Primary spontaneous pneumothorax in adults. http://www.uptodate.com/home/index.html. Accessed Jan. 26, 2011.


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