What causes a barotrauma?

A barotrauma occurs when there is a significant difference in pressure between the inside of an air space in the body, such as the ears, sinuses, or lungs, and the external environment. This condition typically arises when a diver fails to equalize the pressure in these air spaces during a change in depth.

As a diver descends, the surrounding water pressure increases, while the trapped air in the body’s cavities remains at a lower pressure unless equalized. If the diver does not actively equalize by techniques such as the Valsalva maneuver, the pressure difference can lead to the expansion or compression of the air-filled spaces, resulting in pain or injury. This can manifest as a ruptured eardrum in the ears or lung overexpansion injuries.

While rapid descent can contribute to the severity of barotrauma, it is fundamentally the failure to equalize that directly causes the issue. Other choices, like overexertion and exposure to extreme temperatures, do not lead to barotrauma, although they can contribute to other risks associated with diving. Understanding this principle is essential for safe diving practices, as it emphasizes the importance of equalizing pressures routinely during descents and ascents.