PADI Advanced Open Water Practice Exam 2025 - Free Diving Certification Practice Questions and Study Guide

Nitrogen narcosis occurs when a diver is subjected to increased pressure at greater depths, which affects the way nitrogen is absorbed and impacts the nervous system. As a diver descends, the partial pressure of nitrogen in the breathing gas increases, leading to a higher concentration of nitrogen in the body's tissues and blood. This elevated level of nitrogen can result in central nervous system effects that resemble intoxication, such as impaired judgment, reduced motor skills, and altered mental states.

Understanding nitrogen narcosis is crucial for divers, as it can significantly influence their ability to make sound decisions and respond to emergency situations underwater. The effects are typically experienced at depths greater than around 30 meters (100 feet) and can vary depending on the individual and their condition. Recognizing the symptoms allows divers to manage their depth and duration to minimize the risk of narcosis.

The other options describe different conditions or physiological responses that are not related to the specific effects of nitrogen narcosis. For example, breathing regulation issues related to altitude are not influenced by nitrogen pressure in the same manner as at dive depths, and temporary loss of sight or barotrauma pertains to different mechanisms altogether that do not involve the effects of nitrogen on the nervous system.