The double-layer membrane surrounding the lungs is called the pleura, and also covers the inner chest wall. It keeps the chest cavity airtight, however, if air enters the space between the two layers of the pleura, a collapsed lung or pneumothorax occurs. A pneumothorax can be major, requiring immediate medical attention, or minor, requiring no intervention at all. A small collapse will typically resolve on its own, while a larger pneumothorax can be life-threatening requiring the insertion of a chest tube to allow air to escape. If the chest tube is unsuccessful, surgical intervention may be required.
Spontaneous Pneumothorax
During a spontaneous pneumothorax, air passes from the lung into the pleural space by way of a rupture in the pleura next to the lung. The causes are not fully understood, but according to the Mayo Clinic, doctors think the ruptures occur at weak spots in the pleura, usually near the top of the lung. Spontaneous pneumothorax can also occur as a result of lung disease, such as emphysema, tuberculosis, a lung abscess, or cystic fibrosis. For a larger pneumothorax, a chest tube may be necessary to relieve the pressure.
Tension Pneumothorax
A tension pneumothorax occurs when air that has entered the pleural space cannot escape and begins to accumulate. The pressure in the pleural space increases and can compress the lungs and heart, leading to a potentially life-threatening situation. To treat the condition, doctors remove the accumulated air by placing a narrow needle in the space to relieve the pressure, allowing the lung to re-inflate.
Atelectasis
Atelectasis can cause a lung collapse because of obstruction of the air passages or a pulmonary artery. According to the National Heart, Lung and Blood Institute, airway obstruction can result from something as simple as a plug of dry mucus, from an object accidentally inhaled, or from a tumor. A minor lung collapse may have no symptoms at all, but a larger collapse will cause breathlessness, anxiety and pain.
Traumatic Pneumothorax
Force or penetrating injuries to the chest can also cause air to enter the pleura, leading to lung collapse. Air can enter the pleural space from outside the chest or from inside the lung as a result of a surgical procedure, such as a lung biopsy or bronchoscopy. A traumatic pneumothorax can also be the result of cardiopulmonary resuscitation, a deployed air bag or fall.
