Under a subcutaneous emphysema (including subcutaneous emphysema or subcutaneous emphysema ) refers to an ascending or propagating accumulation of gas in the subcutaneous after spontaneous or injury-related opening aerated organs such. B. the lungs . The emphysema can occur, for example, as a result of a peripheral tear in the lung with connection to the mediastinum after a diving accident . It can also arise as a complication after the body cavities have been filled with air as a result of medical diagnostics or after infections with gas-producing pathogens under the skin. Symptoms include the typical "snowball crunch" ( crepitation ) and the swelling of the skin that can be pushed away. Extensive skin emphysema can z. B. caused by a tension pneumothorax, a thoracic tear or skull base fracture with opening of the paranasal sinuses .