What can cause lung overexpansion injuries during scuba diving?

Holding one’s breath while diving can lead to lung overexpansion injuries because of the physics of gas expansion during ascent. When a diver descends, the pressure around them increases, and the air in their lungs is compressed. If a diver holds their breath and starts to ascend, the air in their lungs expands as pressure decreases. This expansion can create excessive pressure in the lungs, which can potentially rupture lung tissue, leading to serious injuries such as pneumothorax (collapsed lung) or arterial gas embolism.

Therefore, it is crucial for divers to continue to breathe normally while ascending. This allows the gases in the lungs to be safely expelled, thereby preventing dangerous overexpansion and ensuring the diver's safety. Adhering to a normal breathing pattern is a fundamental aspect of safe diving practices.