When Scuba Diving, the excessive build up of Carbon Dioxide is mostly a direct consequence of inadequate breathing and ventilation. If levels increase, Carbon Dioxide Toxicity is the result and it can be extremely dangerous causing sedation and shortness of breath.

Causes of Carbon Dioxide Toxicity:
Inadequate ventilation due to;
• Skip breathing
(intermittent breathing while scuba diving)
• Tight wetsuit
• Exertion
• Faulty regulator
• Deep diving
• Contamination of the gas supply (rebreathers)

Signs & Symptoms of Carbon Dioxide Toxicity:
• Rapid breathing
• Headache
• Dizziness
• Flushed appearance
• Nausea
• Vomiting
• Confusion
• Muscular convulsions (with contaminated air supply)
• Unconsciousness (can occur with exertion at depth or contaminated air supply)

First Aid Treatment for Carbon Dioxide Toxicity:
• Flush circuit if using rebreather and/or change of other breathing gas supply
• Return to the surface and breathe fresh air
• Cease movement
• Breathe normally
• Provide oxygen
• Rescue and resuscitate as appropriate in a very severe case