IANTD Open Water Diver Practice Exam 2025 – Complete Test Preparation

Oxygen poisoning, also known as oxygen toxicity, primarily occurs when a person is exposed to high concentrations of oxygen for extended periods, particularly under increased pressure, such as during diving activities. The symptoms listed are classic signs of this condition and stem from the toxic effects of oxygen on the central nervous system.

Muscle twitching and convulsions arise due to the heightened excitability of nerve cells when exposed to oxygen at excessive levels. Nausea and dizziness are common as well, as the body struggles to maintain balance and manage the effects of heightened oxygen levels on metabolism and nerve function. Confusion can result from disruptions in brain activity due to oxygen toxicity, further highlighting the neurological impact of oxygen in such scenarios.

While the other options describe various health issues, they do not align with the typical symptoms associated with oxygen toxicity. Understanding these symptoms is crucial for divers, as recognizing the signs early can lead to timely interventions and prevention of more severe complications.