A temporary alteration of consciousness caused by the affect of breathing gases on the central nervous system. As gases compress they affect the central nervous system and create a feeling of drunkenness and slowed thinking. The primary gas responsible for this effect is nitrogen which causes noticeable symptoms in most divers from approximately 30 meters (100 feet). The effect increases as depth (and pressure) increase – this phenomenon is known as the Martini Effect or Martini's Law.
Nitrogen narcosis is remedied by simply ascending with all effects clearing within minutes of ascending. Narcosis is unpredictable and can affect different people in different ways at different depths. Extreme narcosis can be dangerous due to the diver's reactions and judgments being impaired.