Pneumomediastinum is air in the chest cavity (mediastinum—see Overview of Pleural and Mediastinal Disorders).
The mediastinum, located in the central part of the chest (see Overview of Pleural and Mediastinal Disorders), can become filled with air when
Most often, people have chest pain below the breastbone. The pain may be severe.
When doctors do a physical examination, they may hear a crunching or crackling noise when they listen to the chest through a stethoscope. A chest x-ray is done to confirm the diagnosis.
Usually, treatment is not necessary. However, the problem that caused pneumomediastinum may require treatment.