[Pneumomediastinum: intervention is not always necessary].

Pneumomediastinum is characterized by the presence of free air in the mediastinum. This can be a sign of a severe underlying disorder that requires urgent intervention. However, pneumomediastinum is also associated with other causes that can be treated conservatively. Here, we describe three patients who presented with a primary or spontaneous pneumomediastinum and a secondary pneumomediastinum due to traumatic or iatrogenic perforation. Recognition of the underlying cause of pneumomediastinum is essential for further diagnostic studies and patient management. Unnecessary investigations and interventions, which may cause further harm to and hospitalization of the patient, can thereby be prevented.