What is the term for sudden loss of consciousness due to underwater breath holding?

The term for sudden loss of consciousness due to underwater breath holding is referred to as shallow water blackout. This phenomenon occurs primarily when a person holds their breath for an extended period while submerged in water. As oxygen levels drop and carbon dioxide levels rise, the brain may not receive enough oxygen to function correctly, leading to a loss of consciousness.

Shallow water blackout often happens in situations where individuals engage in breath-holding activities, such as free diving or underwater swimming, without proper supervision or safety measures in place. This condition is particularly dangerous because it can occur without warning and can lead to drowning if the individual does not surface for air.

The other options reflect different concepts: deep water blackout typically involves loss of consciousness due to factors associated with deeper diving, hypoxic collapse is a broader term that refers to any collapse due to inadequate oxygen, and underwater fainting is an informal term and not a recognized medical term. These distinctions help clarify why shallow water blackout is the correct terminology for the scenario in question.