Nitrogen Narcosis: Causes and Effects
If you are new to recreational diving, nitrogen narcosis is a subject that you should be made very aware of.
What is Nitrogen Narcosis?
Nitrogen narcosis (also known as inert gas narcosis) is a condition that divers can begin to experience upon reaching a certain depth while breathing pressurized air. It usually occurs around the 30 meter mark but in truth can affect anyone to some degree at much shallower depths.
What are the Causes of Nitrogen Narcosis?
The exact causes of nitrogen narcosis are not totally understood at the present time. Having said this, we do know that it is related to the way in which nitrogen gas dissolves into the neural nerve membranes under pressure, disturbing nerve transmission in the process.
What are the Effects of Nitrogen Narcosis?
Nitrogen narcosis is extremely dangerous. Most people will discern no obious effect above 30 meters but around the 30 meter mark and below the effects become increasingly vivid.
As its name suggests, nitrogen narcosis has a narcotizing effect on the body. Divers suffering from the condition can experience the following conditions and/or sensations:
- Loss of decision making capability.
- Impaired judgment.
- Impaired coordination.
- Loss of focus.
- Vertigo.
- Panic.
- Anxiety.
- Euphoria.
- Hearing disturbance.
- Dizziness.
- Paranoia.
- Depression.
- Sensations of tingling and numbness in the body’s extremities.
- Feelings of over-confidence and invulnerability.
- Fatigue.
Around the 90 meters mark, the effects of nitrogen narcosis becomes more extreme:
- Visual and aural hallucination.
- Unconsciousness.
What Causes Nitrogen Narcosis to be so Dangerous?
Clearly any impairment in cognitive or perceptual function when you are underwater is dangerous and can lead to basic mistakes in safety practices… or even the complete disregard of them. The effects of nitrogen narcosis can ulitmatley be disastrous, indirectly or directly leading to death.
Nitrogen narcosis can affect any diver be they; experienced or inexperienced, fit or unfit, healthy or unhealthy, fat or thin, old or young. Everyone is susceptible to it but some are more tolerant to it than others. However, nitrogen narcosis tolerance is unpredictable and so those more susceptible to it cannot be identified. Notwithsatnding this, no-one is immune to it and this is why its effects are potentially life threatening for all divers.
Avoiding Nitrogen Narcosis
Nitrogen narcosis can be avoided by avoiding its causes while you are underwater, i.e. keep to recommended recreational diving limits. Be aware of your depth at all times and take particular care if you are approaching the 30 meter mark.
Another way that nitrogen narcosis is avoided underwater is to use a modified air mix to limit or remove nitrogen intake. Where the use of such gases is required though, specialized training would also be required. For recreational divers, nitrogen-free/reduced mixes (such as trimix and heliox) are unnecessary as most basic SCUBA diving courses certify divers for depths above 18 meters only (more advanced recreational diving courses can certify divers to 30 meters).
In order to combat the effects of nitrogen narcosis the diver should simply ascend to a shallower depth: dealing with the causes of nitrogen narcosis in such a way stops the effects very quickly (almost immediately). However, any ascent that you make to mitigate the effects of the narcosis should always be managed properly to avoid decompression sickness, especially in cases where you have been diving near to recommended recreational diving limits.
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