Subcutaneous emphysema is the medical term for air becoming trapped in tissues beneath the skin. It is rare, but may occur as a result of trauma, injury, infection, or certain medical procedures.

Doctors sometimes refer to subcutaneous emphysema as crepitus, tissue emphysema, or subcutaneous air. The condition may be visible if it leads to bulging beneath the skin. It most often affects the skin of the neck or chest but can occur elsewhere.

In this article, we describe what subcutaneous emphysema is, including its symptoms, causes, and treatment. We also outline the possible complications of subcutaneous emphysema, look at the outlook for people with this condition, and list some other types of emphysema.

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The skin comprises an outer layer called the epidermis and an inner layer called the dermis. Beneath the dermis is a layer of subcutaneous tissue that mainly consists of fat and connective tissue.

Subcutaneous emphysema is the presence of air in the subcutaneous tissue. Possible causes include trauma, infections, injuries, and certain medical procedures.

Subcutaneous emphysema itself often does not require treatment. However, the underlying cause may be serious in some cases.

Depending on where the air has become trapped, complications can arise. As such, a person who experiences symptoms of subcutaneous emphysema should seek immediate medical attention to determine and treat the underlying cause.

The symptoms of subcutaneous emphysema differ from those of other types of emphysema and are typically localized to the area of trapped air. A person may notice a smooth bulge in the skin and feel a sensation of pressure in the area. If a person palpates or presses the bulge, it may create a crackling sound.

People may also experience symptoms related to the trauma or injury that caused the SE.

Subcutaneous emphysema itself is typically a benign condition. Generally, the body will simply absorb the air trapped in the subcutaneous tissues.

However, complications can sometimes occur. In some instances, the trapped air can compromise the subcutaneous tissue. When this happens, surgery may be necessary to remove the air.

In some cases, subcutaneous emphysema may indicate a more serious injury or illness that requires rapid intervention.

Subcutaneous emphysema is a rare and generally benign condition. However, trapped air in certain parts of the body may cause complications. The possible complications include:

Air can also move along tissues to other parts of the body and create symptoms related to pressure or swelling.

Subcutaneous emphysema is uncommon but may occur as a result of the following:

  • injury to the chest cavity
  • injury to the sinus cavities
  • injury to the facial bones
  • barometric trauma, which is an injury to the body due to changes in air or water pressure
  • a pulmonary bleb, which is a small collection of air between the lung and the outer surface of the lung
  • bowel perforation
  • infections, such as gas gangrene

Subcutaneous emphysema can also occur following medical procedures that involve placing a tube inside the body. Examples include:

It can also occur due to ventilator malfunction or disruption.

As subcutaneous emphysema can occur as a result of serious trauma, injury, or infection, a person who experiences symptoms of this condition should seek immediate medical attention.

The treatment for subcutaneous emphysema involves identifying and treating the underlying cause. According to a 2021 review, subcutaneous emphysema is likely to resolve within 10 days if a doctor is able to manage the underlying cause.

In some cases, subcutaneous emphysema will occur without any obvious underlying cause. As long as a person is not experiencing significant discomfort, the doctor may recommend a watch-and-wait approach. The body will usually absorb the extra air on its own over time.

There are several types of emphysema, and most affect the lungs. Emphysema involves damage to the tiny air sacs within the lungs, known as alveoli. The alveoli are responsible for exchanging oxygen and carbon dioxide, so damage to these tissues typically results in breathing difficulties and other respiratory problems.

There is no cure for emphysema. However, treatments are available to help manage the symptoms.

Below are some examples of other types of emphysema.


Bullous emphysema is a condition in which damage to the walls of the alveoli causes large pockets of air to develop within the lungs. In comparison with the alveoli, these large air pockets are less efficient in exchanging oxygen and carbon dioxide. As such, a person with bullous emphysema may experience breathing difficulties.

Bullous emphysema is sometimes called vanishing lung syndrome. The reason for this is that on X-ray images, the large air pockets give the appearance of the lung disappearing.

Bullae are larger than 1 centimeter in diameter. Doctors refer to especially large bullae as giant bullae. These are more likely to cause symptoms and require surgical treatment.


Paraseptal emphysema is also called distal acinar emphysema. It typically occurs in the upper lobes of the lungs and rarely affects the entire lung. This type of emphysema can develop into bullous emphysema.

As paraseptal emphysema is commonly linked to smoking, quitting smoking is an important part of the treatment for this condition.


Panlobular emphysema typically affects the lower lobes of the lungs and involves extensive damage to the alveoli. Possible causes of panlobular emphysema include:

  • Alpha-1 antitrypsin deficiency: This rare inherited disorder may cause lung disease.
  • Ritalin lung: This term refers to lung changes associated with injecting talc-containing methylphenidate, such as Ritalin.
  • Obliterative bronchiolitis: In people with this disease, the smallest airways of the lungs become obstructed due to inflammation.
  • Swyer-James syndrome: This rare condition occurs when a lung or part of a lung does not grow properly following obliterative bronchiolitis.

Subcutaneous emphysema is a rare type of emphysema involving air trapped beneath the skin. It is usually a benign condition. However, it can sometimes occur as a result of severe trauma or an injury or infection that requires prompt treatment. As such, anyone who experiences symptoms of subcutaneous emphysema should seek immediate medical attention.

In those with subcutaneous emphysema, the body will typically absorb any trapped air over time. However, depending on the location of the trapped air, a doctor may need to perform surgery to release it.

Unlike other types of emphysema, subcutaneous emphysema does not primarily affect the lungs. Most instances of subcutaneous emphysema affect the skin on the neck or chest, though the condition can also occur elsewhere on the body.