An Overview of Pneumothorax

What You Should Know About a Collapsed Lung

Lungs don't collapse as much as get squished by high pressure. BSIP/UIG / Getty Images

A pneumothorax occurs when air collects in a space located between the lung and the chest wall (called the pleural space). This collection of air exerts pressure on the lung, eventually causing it to collapse. Like a balloon, once collapsed, the lung cannot properly inflate and bring oxygen into your body, and this causes symptoms like chest pain and trouble breathing.

While trauma to the lung or a chronic lung condition, like chronic obstructive pulmonary disease (COPD), may cause a pneumothorax, pneumothoraces may also occur on their own without any underlying culprit.

The diagnosis of a pneumothorax involves a medical history and physical examination. An imaging test, like a chest X-ray or computed tomography (CT) scan, is used to confirm the diagnosis.

The treatment of pneumothorax depends on several factors and may range from simple oxygen supplementation and monitoring to urgently reducing the air pressure in the chest with a needle or chest tube.


Pneumothorax may occur for a number of different reasons, including the following:

Sometimes, though, a pneumothorax occurs for no reason at all—this is called a primary spontaneous pneumothorax. Factors that have been found to increase a person's chance for developing a primary spontaneous pneumothorax include:

  • Smoking
  • Male gender
  • Having a family history of pneumothorax


There are two main types of pneumothoraces—simple and tension.


With a simple pneumothorax, air escapes the lung and becomes trapped between the lining of the chest wall (called the parietal pleura) and the sac surrounding the lungs (called the visceral pleura). The air-trapping between these two membranes forces them apart (in healthy patients, these two pleura normally slide against one another with breathing).

As the air accumulates within this space, the lung becomes more and more compressed, causing it to eventually collapse.


Much less commonly, a tension pneumothorax may develop. With this life-threatening type of pneumothorax, there is enough air pressure built up to interfere with blood flow to the heart, causing low blood pressure, a high heart rate, and severe breathlessness.

Tension pneumothorax is more likely to occur with trauma, when there is an open wound in the chest allowing air to come in, and in patients who are on a breathing machine.


The two main symptoms of pneumothorax are:

Any chest injury followed by shortness of breath should be seen by a doctor. For severe shortness of breath after an injury, call 911.


The diagnosis of a pneumothorax involves a medical history, physical examination, and imaging tests. Blood tests may be performed (mostly to rule out alternative diagnoses).

Medical History and Physical Examination

Besides accessing your symptoms and risk factors for developing a pneumothorax, your doctor will perform a physical exam.

Interestingly, with small pneumothoraces, there are sometimes no obvious findings on the physical exam. If the pneumothorax is large enough, however, a doctor will note diminished lung sounds on the affected side (air movement is restricted, so the sound is less obvious when the patient takes a breath).

Hyperresonant percussion (increased resonance is heard when the doctor taps on a patient's chest wall) is another physical exam finding. Sometimes, a person with a pneumothorax will exhibit labored breathing and/or accessory muscle use.

High heart rate and low blood pressure on physical examination are potentially life-threatening signs of a tension pneumothorax and looming cardio-respiratory arrest.

Imaging Tests

Imaging tests used to diagnose a pneumothorax may include:

Blood Tests

There is no specific blood test to diagnose a pneumothorax. An arterial blood gas may be performed to test for respiratory acidosis, which is an acid-base imbalance that occurs in the body as a result of excess carbon dioxide buildup from a pneumothorax.

Blood tests, such as a D-dimer or cardiac enzymes, are often performed to rule out alternative diagnoses, like a blood clot in the lung or a heart attack.


The treatment of pneumothorax depends on the size of the air leak, the underlying cause (if one is present), and your symptoms.

With that, here are some of the different strategies used to manage a pneumothorax:


Small, spontaneous pneumothoraces do not always necessitate invasive treatment, as they rarely cause breathing problems or progress to a tension pneumothorax. In fact, most resolve on their own.

In these cases, your doctor may monitor you for a day or so in the hospital with oxygen, and then have you follow-up closely with serial X-rays to ensure improvement.

Needle Decompression or Chest Tube Drainage

For a large pneumothorax, or if you are experiencing breathing problems, your doctor will need to remove the air that has leaked outside your lung. This is done using a needle (placed in between your ribs) attached to a syringe to pull out the air.

Alternatively or in addition to, a tube (called a chest tube) may be placed in between your ribs to remove the air over the course of a few days.

Important Note

Tension pneumothoraces are treated with urgent needle decompression (sometimes by a paramedic or other emergency medical technician) followed by transport to a hospital and chest tube placement.


Sometimes, lung surgery is required to treat a pneumothorax. With an open thoracotomy (which is a major surgical procedure), a surgeon makes an incision in between your ribs within your chest wall in order to access the pleural cavity and remove the collections of air.

An alternative, minimally invasive approach is called video-assisted thoracoscopic surgery (VATS). With VATS, a surgeon will insert a tiny video camera (called a thoracoscope) and long, thin surgical instruments into small cuts between your ribs where the air is located. This can help the surgeon remove the air-filled spaces.


Pleurodesis is often the final step, as its goal is to prevent a pneumothorax from happening again. This procedure entails obliterating the pleural space where the air collected to prevent the lung from collapsing again.

Pleurodesis can be done mechanically, whereby a surgeon uses a piece of dry gauze to roughen up the outer pleural membrane, or chemically, whereby a chemical substance, like talc, is placed between the outer and inner pleural membrane. Often times, chemical pleurodesis may be performed during the VATS procedure.

A Word From Verywell

Two key take-home points is that a pneumothorax can vary in severity from mild to potentially life-threatening, and the symptoms of a pneumothorax (chest pain and shortness of breath) can mimic those of many other serious health conditions.

If you are experiencing symptoms of a pneumothorax, the most important thing you can do is to seek medical attention right away.

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