What Is Pneumothorax?

A.K.A Collapsed Lung

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A pneumothorax is an accumulation of air or gas in the space between the lung and the chest wall that occurs when a hole develops in the lung that allows air to escape. This causes the lung to partially or completely collapse, hence the condition's other name: collapsed lung. In the United States, 5 million people are treated for it each year.

Doctors examining x-ray of chest and ribs on digital tablet
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In the past, it occurred most frequently in conjunction with tuberculosis. Today, smoking is by far the greatest risk factor. People who have chronic obstructive pulmonary disease (COPD) are at greater risk for pneumothorax than others because the structure of their lungs is weak and vulnerable to the spontaneous development of these types of holes.


Symptoms of pneumothorax may develop during rest, sleep, or while awake, or as a result of sudden trauma such as a chest wound. A small pneumothorax may even go unnoticed, since it is not always accompanied by symptoms.

Symptoms of a large pneumothorax include:

  • Sharp chest pain that gets worse when coughing or taking a deep breath and that may radiate to the shoulder, arm, or back
  • Shortness of breath (dyspnea) or shallow breathing
  • Chest tightness
  • Being easily fatigued
  • Blue or ashen skin (cyanosis, caused by lack of oxygen)
  • Rapid heart rate (tachycardia)

Other symptoms may include distended neck veins, nasal flaring, anxiety, or low blood pressure (hypotension).

Since symptoms can range from mild to severe, it’s not uncommon for it to take several days to realize something is wrong and seek treatment. If you develop any symptoms of pneumothorax, be sure to seek immediate medical attention. In some cases, it can be a life-threatening emergency.


Pneumothorax can be caused by a number of diseases and conditions. There are two general types:

  • Spontaneous pneumothorax can occur without a prior diagnosis of lung disease or as a complication of a known lung disease such as COPD, cystic fibrosis, emphysema, asthma, tuberculosis, or whooping cough. In fact, 70% of spontaneous pneumothorax cases occur in people with COPD.
  • Traumatic pneumothorax can be caused by an injury to the lung, such as a gunshot, knife wound, or rib fracture. The lung can also be punctured during certain medical procedures, such as a biopsy or venous catheterization.

Another cause of spontaneous pneumothorax are blebs (a small collection of air between the lung and the outer surface of the lung (visceral pleura); these are likely formed during embyrogenesis and mostly affect young men.

Rarely, for reasons not well understood, women may experience a non-traumatic pneumothorax during their menstrual period called catamenial pneumothorax. This condition occurs when endometrial tissue becomes attached to the thorax and forms cysts. The cysts can release blood and air that enter the pleural space, causing the lung to collapse.

Risk Factors

Men—especially tall men—under the age of 40 and whites of non-Hispanic origin are most at risk for this disorder. In the United States, the incidence is about 7 in 100,000 for men, and 1 in 100,000 women each year.

Smoking is the most significant risk factor for spontaneous pneumothorax. For smokers, the lifetime risk is as high as 12%, compared to 0.1% in those who have never smoked.

Pneumothorax can also run in families. As many as one in 10 people who experience a pneumothorax that occurs for no known reason have a family history of the disorder.

Sometimes the cause of the pneumothorax may be impossible to determine. There is no way to prevent a pneumothorax, but you can reduce your risk by not smoking.


Your healthcare provider may determine you have pneumothorax during a physical examination by listening through a stethoscope and identifying decreased or absent breath sounds on the affected side of the lung.

In addition, the chest wall, which normally rises equally on both sides upon inhalation, may show an inability to rise on the affected side.

Tests that support a diagnosis of pneumothorax include:

  • Chest X-ray
  • Utrasonography
  • Computerized tomography (CT)
  • Arterial blood gas testing, which measures blood oxygen and carbon dioxide levels


In some cases, smaller pneumothoraces go away on their own. However, a large pneumothorax will require hospitalization.

To treat a pneumothorax, a needle must be inserted between the ribs into the space between the lung and the chest wall in a procedure called needle aspiration to help remove the air and re-inflate the lung.

A chest (thoracostomy) tube may then be inserted and will stay in place for one day or several days (depending on the cause of the pneumothorax) while you recover in the hospital. If the pneumothorax recurs, video-assisted thoracic surgery may be required.

Inserting the tube or needle can be painful, so you may receive painkillers by IV or regional anesthesia. You may also be given antibiotics to prevent infections. If you’re treated in an emergency room, you might receive a referral to a thoracic surgeon or pulmonologist for further care.

Recovery and Recurrence

If you have a pneumothorax, you should not fly until you’ve received stabilizing treatment (such as with a thoracostomy tube). You also should not fly or scuba dive for two weeks following discharge from a hospital after being treated. If you have a history of recurrent pneumothorax, always use caution when engaging in these activities.

The risk of having another pneumothorax is highest in the first 30 days after your first occurrence. Over the next year, the risk of having another also remains higher than normal. Estimates of recurrence vary from 20% to up to 60% during the first three years.

The good news is that once a pneumothorax has healed, there are usually no long-term complications.

A Word From Verywell

Because it affects one of the body’s most basic functions—breathing—experiencing a pneumothorax may be frightening. It’s important to remember that, while it’s a serious condition, it is highly treatable. Prompt medical care and continuing to take care of your lungs and health over time will help ensure a full recovery. 

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  3. Primary spontaneous pneumothorax. Genetics Home Reference. MedlinePlus. August 18, 2020.

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By Deborah Leader, RN
 Deborah Leader RN, PHN, is a registered nurse and medical writer who focuses on COPD.