Pneumomediastinum is a condition in which air enters the mediastinum due to some blunt trauma or injury. Read on to find out more about this specific medical condition, including its symptoms, causes, diagnosis and treatment.

Pneumomediastinum Definition

It is a health condition characterized by the presence of air in the mediastinum. The word “Pneumomediastinum” has been derived from the Greek word “pneuma”, which means air. The condition was first described by René Laennec in the year 1819. Pneumomediastinum can be caused by some physical trauma or any other situation that causes the air from lungs, airways or the bowels to enter the chest cavity. This disorder is also referred to as “Mediastinal emphysema”.

Pneumomediastinum Causes

This rare disease can be caused by some disease or injury. In most cases, it occurs when air leaks into mediastinum from any section of the lungs or the airways. This usually happens when there is increased pressure on the lungs or the airways due to:

Picture of Pneumomediastinum

Picture 1 – Pneumomediastinum

  • Excessive coughing
  • Vomiting
  • Sneezing
  • Repeatedly bearing down due to increasing abdominal pressure such as in a bowel movement or childbirth
  • Deterioration of ulcerative colitis
  • Use of recreational drugs, like Crack Cocaine

The condition can also arise due to other factors like:

  • Blunt chest trauma
  • Retroperitoneal surgery
  • Esophageal rupture, as in Boerhaave syndrome, esophageal carcinoma or endoscopic intervention
  • Tracheobronchial perforation due to laceration, laryngeal fracture, bronchoscopy, tracheostomy or bronchial stump dehiscence
  • Vigorous physical exercise, such as weightlifting or valsalva maneuver
  • Asthma or other similar conditions that can lead to alveolar rupture
  • Stab wounds
  • Infections such as tuberculosis, mediastinitis, dental infection, histoplasmosis, retropharyngeal infection and pneumothorax
  • Pulmonary interstitial emphysema
  • Subcutaneous emphysema
  • Bowel ruptures that can cause the air in the abdominal cavity to move up to the chest

Pneumomediastinum can also result from pulmonary barotrauma, which occurs when an individual travels to or from some higher pressure zone, as in scuba diving or free-diving. The condition can also be induced by physicians to assist Thoracoscopic surgery.

Spontaneous Pneumomediastinum

It is a special form of Pneumomediastinum which develops spontaneously without the aid of any external injury, chest trauma, esophageal or endobronchial procedures, mechanical ventilation, neonatal lung disease, chest surgery or any other invasive procedures.

Pneumomediastinum Symptoms

The disease can be both symptomatic and asymptomatic. It is primarily characterized by severe pain at the middle of the chest that may spread to the neck and arms of patients. The pain gets worse while breathing or swallowing. Other notable symptoms of the disorder include:

  • Voice distortion
  • Labored breathing
  • Subcutaneous emphysema

This health problem is frequently detected on auscultation by Hamman’s crunch, a crunching sound that is heard along with one’s cardiac cycle.

Pneumomediastinum Diagnosis

The diagnosis of Mediastinal emphysema can be either carried out by an X-ray, which will display a radiolucent outline in the region of the heart and the mediastinum, or by a CT scan of the thorax. These tests allow physicians to determine whether there is any hole or fracture in the esophagus or trachea or if there is air in mediastinum.

Pneumomediastinum Differential Diagnosis

The disorder must be properly distinguished from certain other conditions, such as:

  • Pneumopericardium
  • Medial pneumothorax
  • Mach bands

Pneumomediastinum Treatment

In most cases, the disease does not require any special treatment. The condition is treated conservatively as the mediastinum tissues gradually reabsorb the air within the cavity. Breathing in high concentrations of O2 can actually increase absorption of air. Physicians may use a chest tube to release air in case of a collapsed lung or pneumothorax. Surgeries are required to repair any holes or fractures in the esophagus, trachea or bowel.

Pneumomediastinum Prognosis

The outcome of the disorder depends on the factors that caused it in the first place.

Pneumomediastinum Complications

Certain complications may arise while dealing with the disorder, which should be resolved immediately. These health problems include:

Image of Pneumomediastinum

Picture 2 – Pneumomediastinum Image

Lung collapse

The air can gradually build up and then enter the pleural space around the lungs, thereby causing the lungs to collapse.


In some rare cases, air can enter the pericardial cavity and cause a condition known as pneumopericardium.

Cardiac malfunction

In some cases, a large volume of air at the center of the chest creates pressure on the heart and the blood vessels. This makes it difficult for them to work properly.


Although Pneumomediastinum can cause significant chest pain, in most cases patients recover after some time with little difficulty. However, it is advisable to consult a doctor if one is experiencing severe chest pain or difficulties in breathing. Proper medical attention makes management of the disorder easy and relatively less painful.



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