Pneumomediastinum is a medical condition in which air escapes a lung and gets trapped in the chest cavity. It usually occurs when one of the tiny air sacs in a lung ruptures, releasing a small amount of air into the inner chest space called the mediastinum. Depending on the amount of air that escapes, pneumomediastinum can cause significant chest pains and shortness of breath. Most cases go away on their own, but a doctor may decide to manually suction air out of the chest if symptoms are severe.
Many different factors can lead to air buildup in the mediastinum. Air sacs in the lungs called alveoli may become irritated and punctured due to excessive pressure from a sneeze, cough, or hard laugh. Respiratory infections and asthma can increase the chances of an alveolar tear. In addition, direct trauma to the chest or throat can cause internal damage and lead to an air leak. Breathing in carcinogens from cigarette smoke, industrial chemicals, and dust also contribute to lung damage and ruptures.
In most cases, pneumomediastinum is so mild that it does not cause physical symptoms or health complications. A doctor may only notice air buildup when a patient undergoes an exam for an unrelated condition. When symptoms are present, they usually include a chronic dull pain underneath the breastbone, radiating aches through the chest and shoulders, and moderate breathing difficulties. If a lung partially or fully collapses, sharp pains, chest tightness, and severe shortness of breath tend to occur. An individual who experiences any abnormal chest pains or breathing problems should visit a doctor or go to the emergency room.
A physician can check for pneumomediastinum and any underlying problems by performing a series of diagnostic imaging tests. X-rays can confirm the presence of air in the mediastinum, and computerized tomography scans can reveal physical lung abnormalities. A doctor may also decide to collect a blood sample to examine oxygen and carbon dioxide levels. Treatment decisions are made based on the amount of escaped air present and the severity of the patient's symptoms.
Many cases of pneumomediastinum do not require medical care. Small alveolar or esophagus tears usually repair themselves within a few weeks, and excess air is reabsorbed by body tissue. If pain and chest tightness cause discomfort, a doctor may decide to insert a needle and chest tube to draw the air out of the mediastinum. Surgery may be necessary if a lung fully collapses to repair and reinforce damaged tissue. Following medical or surgical care, patients are encouraged to stop smoking, engage in regular exercise, and schedule periodic checkups to help prevent recurring lung problems.