A collapsed lung (pneumothorax) is a buildup of air in the space between the lung and the chest wall (pleural space). As the amount of air in this space increases, the pressure against the lung causes the lung to collapse. This prevents your lung from expanding the right way when you try to breathe in. You will likely have shortness of breath and chest pain.

A pneumothorax may become deadly if the pressure in your chest prevents the lungs from getting enough oxygen into the blood.

Symptoms depend on the size of the pneumothorax. In minor cases, you may not realize you have a pneumothorax. In more severe cases, symptoms will develop rapidly and may lead to shock.

Symptoms may include:

• Shortness of breath (dyspnea). This may be mild to severe, depending on how much of the lung is collapsed.
• Sudden, severe, and sharp chest pain on the same side as the collapsed lung.

Symptoms may become worse with altitude changes (such as flying in an airplane or going underground or underwater).

A pneumothorax usually is diagnosed through a physical exam and a chest X-ray. Your doctor may also do blood tests to measure the level of oxygen in your blood. You may need a CT scan or ultrasound to diagnose the severity of your condition. These tests will also help the doctor plan your treatment.

Treatment can depend on the cause and severity of the pneumothorax. Treatment can also depend on whether the pneumothorax has returned. Some people stay in the hospital for treatment. A minor pneumothorax may heal with rest, but you will need to be checked by your doctor. In some cases, oxygen may be given (through a mask). More serious cases are treated by placing a needle or a chest tube into the chest cavity. Both of these treatments relieve the pressure on the lung and allow it to expand again. Sometimes surgery is done.