injuries and poisoning
Gas Toxicity During Diving
High Pressure Neurologic (Nervous System) Syndrome
A poorly understood set of neurologic symptoms can develop when people dive deeper than 500 to 600 feet (150 to 180 meters), particularly when the dive is rapid and the diver breathes a mixture of helium and oxygen. Symptoms include nausea, vomiting, tremors, clumsiness, dizziness, fatigue, sleepiness, muscle jerks, stomach cramps, and confusion. The syndrome resolves on its own when people ascend or when the rate of descent is slowed. 