Why is hypoxia a greater concern in freediving than in scuba diving?

Hypoxia is a significant concern in freediving primarily due to the nature of breath-holding. When engaging in freediving, divers inhale air before diving and hold their breath while submerged. This increases the risk of hypoxia because as the body consumes oxygen while underwater, carbon dioxide levels build up, signaling the body to surface for air. Without the ability to breathe, divers can experience a rapid decline in oxygen levels, leading to hypoxia, which can cause disorientation, loss of consciousness, or even drowning.

In contrast, scuba diving utilizes tanks filled with compressed air, allowing divers to breathe continuously throughout their dive. This means that even if a diver experiences a drop in oxygen levels, they can compensate by accessing more air from their tank, significantly reducing the risk of hypoxia. This distinction highlights why freedivers are at a greater risk in regard to oxygen availability, making breath-holding practices a critical aspect of safety in that discipline.