Hello, Welcome to HCM, Pneumomediastinum is a condition in which air is present in the mediastinum.It can be due to oesophageal rupture, asthma, bowel rupture, blunt chest trauma, infections like mycoplasma pneumoniae pneumonia and obesity. Most of the patient will present with severe chest pain, difficulty in breathing, change in voice and subcutaneous emphysema. Usually patients can be managed by Conservatively with breathing high flow oxygen. Needle may be inserted into the cavity, releasing the air. Surgery may be needed to repair the hole in the trachea esophagus or bowel. Thank you.