Pneumothorax (Collapsed Lung)

Front view of male chest showing partially collapsed right lung.

A pneumothorax occurs when air fills the space between your lung and chest wall (pleural cavity). This can cause all or part of your lung to collapse. The main cause of a pneumothorax is an injury to the chest cavity that punctures the lungs. Damage may result from a stab or gunshot wound, car accident, fall, or certain surgeries. In some cases, a pneumothorax happens without an obvious cause (spontaneous). 

You're more likely to have spontaneous pneumothorax if you smoke or have a chronic lung disease, such as emphysema.

When to go to the emergency room (ER)

Serious pneumothorax can be fatal if not treated. Call 911 for a bad chest wound or any of the following symptoms:

  • Sudden, sharp chest pain that may spread to your shoulder or back

  • Shortness of breath or trouble breathing

  • A bluish color to the skin

  • Loss of consciousness or feeling faint with any of the above symptoms

What to expect in the ER

  • You will be examined carefully.

  • Your lungs and heart will be listened to through a stethoscope.

  • You may have X-rays or a CT scan. A CT scan combines X-rays and computer scans to provide detailed pictures of your lungs.

  • You will be given help with breathing if you need it.


  • If the pneumothorax is small, you may stay in the ER for 5 to 6 hours to see if it gets any worse. If it does not get worse, you may be sent home without treatment and told to follow up with your regular doctor.

  • If the pneumothorax needs treatment, you will be admitted to the hospital. A healthcare provider may remove the air in your pleural cavity with a needle. Or the provider may place a hollow chest tube in your chest. This tube is attached to a suction device that removes the air. In that case, you will be admitted to the hospital for a few days.

After treatment, you will be told what to do to care for yourself and when to follow up with your doctor.

Health Encyclopedia

Better understand thousands of conditions and treatments: