Pneumothorax (Collapsed Lung)

Medically Reviewed on 8/14/2023

What is a pneumothorax?

Picture of Pneumothorax (Collapsed Lung)
Picture of pneumothorax (collapsed lung)

A pneumothorax is a collection of free air in the chest outside the lung that causes the lung to collapse.

What is tension pneumothorax?

In some instances, the lung continues to leak air into the chest cavity which results in compression of the chest structures, including vessels that return blood to the heart. This is referred to as tension pneumothorax and can be fatal if not treated immediately.

What are the types of pneumothorax?

The types of pneumothorax include the following:

  • A spontaneous pneumothorax, also referred to as a primary pneumothorax, occurs in the absence of a traumatic injury to the chest or a known lung disease.
  • A secondary (also termed complicated) pneumothorax occurs due to an underlying condition.

What causes pneumothorax?

The lungs normally inflate by increasing the size of the chest cavity, resulting in a negative (vacuum) pressure in the pleural space (the area within the chest cavity but outside the lungs). If air enters the pleural space either by a hole in the lung or the chest wall, the pressure in the pleural space equals the pressure outside the body. Thus, the vacuum is lost and the lung collapses.

Spontaneous pneumothorax is caused by a rupture of a cyst or a small sac (bleb) on the surface of the lung. Pneumothorax may also occur following an injury to the chest wall such as a fractured rib, any penetrating injury (gunshot or stabbing), surgical invasion of the chest, or may be deliberately induced to collapse the lung.

A pneumothorax can also develop as a result of underlying lung diseases, including:

Who is at risk for pneumothorax?

Spontaneous pneumothorax is more common in men. Additionally, smoking has been shown to increase the risk of spontaneous pneumothorax.

What are the symptoms of pneumothorax?

Symptoms of a pneumothorax include the following:

  • Chest pain that usually has a sudden onset
  • Sharp pain that may lead to feelings of tightness in the chest
  • Shortness of breath
  • Rapid heart rate
  • Rapid breathing
  • Cough
  • Fatigue

The skin may develop a bluish color (termed cyanosis) due to decreases in blood oxygen levels.


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How do doctors diagnose pneumothorax?

Examination of the chest with a stethoscope reveals decreased or absent breath sounds over the affected lung. Chest X-ray can confirm the diagnosis.

What is the treatment for pneumothorax?

Small Pneumothorax Treatment

A small pneumothorax without underlying lung disease may resolve on its own in 1-2 weeks.

Large Pneumothorax Treatment

A larger pneumothorax and a pneumothorax associated with underlying lung disease often require aspiration of the free air and/or placement of a chest tube to evacuate the air.

Possible complications of chest tube insertion include:

  • Pain
  • Infection of the space between the lung and chest wall (the pleural space)
  • Hemorrhage (bleeding)
  • Fluid accumulation in the lung
  • Low blood pressure (hypotension)

In some cases, the leak does not close on its own. This is called a bronchopleural fistula (punctured lung) and may require chest surgery to repair the hole in the lung.

What is the prognosis for pneumothorax?

The outcome of pneumothorax depends upon the extent and type of pneumothorax.

  • A small spontaneous pneumothorax will generally resolve on its own without treatment.
  • A secondary pneumothorax (even when small) associated with the underlying disease is much more serious and has a significant death rate. A secondary pneumothorax requires urgent and immediate treatment.

Having one pneumothorax increases the risk of developing the condition again. Most recurrences occur within the first year.

Medically Reviewed on 8/14/2023
The American Lung Association