Which symptoms may indicate hyperoxia during a dive?

The symptoms that may indicate hyperoxia during a dive include dizziness, difficulty concentrating, and visual disturbances. Hyperoxia occurs when there is an excess of oxygen in the body, often due to breathing gas mixtures with a high partial pressure of oxygen.

As divers are exposed to elevated levels of oxygen, particularly at deeper depths or while using enriched air nitrox, they can experience central nervous system effects. Dizziness is a common neurological symptom that can arise from the brain being exposed to higher-than-normal oxygen levels. Difficulty concentrating can occur because of the impact hyperoxia has on cognitive function, leading to confusion or an inability to focus. Visual disturbances, such as blurriness or tunnel vision, are also indicative of how hyperoxia can affect the nervous system and perception.

These symptoms warrant immediate attention, as they can escalate to more severe neurological issues if not addressed promptly. A diver experiencing these signs should ascend to a shallower depth to reduce the partial pressure of oxygen in the breathing gas, ideally taking preventative measures against hyperoxia.