What Is It?

A pneumothorax is commonly known as a collapsed lung. Normally, the outer surface of the lung sits next to the inner surface of the chest wall. Thin membranes called pleura cover both surfaces. A pneumothorax occurs when air escapes from the lungs or leaks through the chest wall and enters the space between the two membranes (pleural cavity). As air builds up, it causes the nearby lung to collapse.

Most cases of pneumothorax result from an injury to the lungs or chest wall, such as:

  • A penetrating injury, such as a knife or gunshot wound
  • Blunt trauma from a fall or car accident
  • Medical procedures, such as removal of fluid from the pleural cavity with a needle (thoracentesis) or a lung biopsy

Occasionally, a collapsed lung can occur without any direct injury to the lung or chest. This is called a spontaneous pneumothorax. Often, this results from lung damage caused by diseases such as asthma, cystic fibrosis and pneumonia. It is particularly common in emphysema, which causes air-filled sacs, called blebs, to form. When a bleb bursts, air is released into the pleural cavity, triggering a pneumothorax. A spontaneous pneumothorax also can develop in people who don’t have any obvious lung disease. It’s most common in tall, thin men between the ages of 20 and 40, and is much more common in smokers. Some people who don’t have any obvious lung disease have blebs that can rupture and cause this type of spontaneous pneumothorax.

Another type of collapsed lung called tension pneumothorax sometimes occurs when a growing air pocket causes increased pressure within the pleural cavity. This collapses the nearby lung and can push the heart and major blood vessels to the unaffected side of the chest. This movement, called a mediastinal shift, can cause a life-threatening drop in blood pressure. Tension pneumothorax most commonly occurs in people with penetrating chest injuries. It also occurs in people on ventilators or those who have undergone Cardiopulmonary resuscitation.

Pneumothorax occurs in about nine of every 100,000 people each year.


Symptoms of pneumothorax include:

  • Sudden shortness of breath
  • Painful breathing
  • Sharp chest pain, often on one side
  • Chest tightness
  • Dry, hacking cough
  • Bluish color skin (because of a lack of oxygen)
  • Engorgement of the neck veins (in tension pneumothorax)
  • Low blood pressure or shock (in tension pneumothorax)
  • Rapid heartbeat


Your doctor may suspect pneumothorax if you suddenly develop shortness of breath or chest pain, especially if you have had trauma to the chest. He or she will ask about your symptoms, your medical history and your smoking habits.

Your doctor’s physical examination will focus on your general appearance, your vital signs (temperature, pulse, breath rate, blood pressure), and your heart and breath sounds. Typical exam findings in pneumothorax might include:

  • Low blood pressure
  • Rapid heart rate
  • Low levels of blood oxygen
  • Loss of normal breath sounds in the part of the chest where the lung is deflated
  • A hollow sound when the fingers are tapped on part of the chest
  • A shift in the normal location of heart sounds

A chest X-ray is the best way to confirm that you have a pneumothorax. The X-ray will show the pneumothorax as a dark area in the chest. A Computed tomography (CT) scan may be needed in some cases to find a small pneumothorax or for people with extensive lung disease.

Your doctor may check the oxygen level in your blood with a handheld device called a pulse oximeter, or draw blood from an artery in the wrist (an arterial blood gas test) to directly measure the levels of oxygen and carbon dioxide in your blood. He or she also may order an electrocardiogram (EKG), an electrical test of the heart.

Expected Duration

Once the cause of pneumothorax is treated, a collapsed lung usually will return to normal within 48 to 72 hours. Recovering from a collapsed lung may take up to several weeks.


Most cases of pneumothorax cannot be prevented. Quitting smoking can reduce your risk of developing the types of lung disease associated with pneumothorax. Wearing your seat belt in the car and avoiding other activities that put you at risk of chest injuries can help you to avoid a pneumothorax caused by trauma.


A pneumothorax can be treated in several different ways. Your doctor will choose the right treatment based on several factors, including the size and location of the pneumothorax and your medical condition. Almost everyone receives 100-percent oxygen through a facemask. Additional treatment options include:

  • Careful observation by a doctor to see if the condition corrects itself on its own
  • Removal of the air from the pleural cavity with a needle and syringe
  • Removal of the air from the pleural cavity by inserting a hollow plastic tube, called a chest tube, between the ribs, and attaching it to a suction device

You may be treated or observed for several days to make sure the pneumothorax goes away completely. If you have had a serious chest injury, or treatment does not expand your lung, your doctor will discuss the possibility of surgery to repair the lung and pleura. Sometimes damaged or scarred portions of lung are removed to allow the pneumothorax to heal. Traditional surgery requires the chest to be opened. But newer techniques using tiny cameras (thoracoscopy) cause less scarring and result in faster recovery times.

People with repeated episodes of pneumothorax may need treatment to prevent further recurrences. Options include:

  • Surgery that removes blebs or areas of scarring or attaches the lung permanently to the chest wall
  • A chemical injection that fuses the lung and chest wall together (pleurodesis)

When To Call A Professional

Call your doctor if you have symptoms of pneumothorax, especially if you have lung disease or have had a collapsed lung before. Even if your symptoms seem to improve, call your doctor. Some people with pneumothorax have decreasing chest pain and shortness of breath in the first 24 hours, but the pneumothorax is still present.


Once a pneumothorax has healed, there is usually no long-term effect on your health. However, up to 50 percent of people have another pneumothorax, especially within a few months of the first one. To decrease the risk of a pneumothorax occurring again:

  • Stop smoking.
  • Avoid changes in air pressure, such as from flying in unpressurized aircraft or scuba diving.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.