What should a diver do if they experience symptoms of oxygen toxicity?

When a diver experiences symptoms of oxygen toxicity, ascending to a lower pressure immediately is the correct response. Oxygen toxicity can occur when divers use enriched air nitrox that is too rich in oxygen for the specific depth they are at, leading to potential neurological or pulmonary complications. Symptoms can include visual disturbances, muscle twitching, nausea, and seizures.

By ascending, the diver reduces the ambient pressure, which in turn decreases the partial pressure of oxygen in the breathing mix. As the pressure decreases, the risk of oxygen toxicity is mitigated, allowing the body to recover from the effects. Remaining at depth or increasing depth would only worsen the situation, increasing the likelihood of serious complications. Notifying a dive buddy is important for safety but should come after taking the immediate necessary action to ensure personal health by ascending.