Subcutaneous emphysema is characterized by what condition?

Subcutaneous emphysema is characterized by air being trapped beneath the skin. This condition usually occurs when air escapes from the lungs or respiratory system and enters the subcutaneous tissue. It can be the result of a variety of medical situations, such as trauma, surgery, or certain diseases that allow air to leak into the skin's layers. The presence of air under the skin can create a characteristic swelling or "crepitus" sensation, which is often palpable when pressed.

While options discussing gas bubbles in the bloodstream, fluid accumulation in tissues, and pressure imbalances in the chest address other specific medical issues, they do not accurately define subcutaneous emphysema, which is strictly related to the presence of air in the subcutaneous tissue.