What symptom usually indicates nitrogen narcosis?

An altered mental state or impairment is the primary symptom that typically indicates nitrogen narcosis. This condition occurs when a diver breathes nitrogen at depths greater than about 30 meters (100 feet). The high partial pressure of nitrogen at these depths can lead to effects similar to those of alcohol intoxication, resulting in a decrease in cognitive function, impaired judgment, reduced awareness, and loss of coordination. Divers experiencing altered mental states may find it difficult to make rational decisions, which can be dangerous in an underwater environment where clear thinking is essential for safety.

While excessive buoyancy, difficulty breathing, and loss of hearing can also occur in divers, they are not specific indicators of nitrogen narcosis. These symptoms may be related to other diving issues and do not inherently signify the effects of nitrogen on the nervous system like altered mental states do. Understanding nitrogen narcosis and recognizing its symptoms are crucial for divers to ensure their safety and maintain awareness of their physical and mental condition while submerged.