Nitrous oxide has been safely used as a mild anaesthetic for over 150 years. Problems with its use come primarily from carelessness. Potential problems include :

• Brain injury and suffocation can result from lack of oxygen. When used as an anaesthetic, nitrous is always administered in combination with oxygen. Never use nitrous in any manner that does not provide for adequate oxygen intake.
  
  Note that it is not necessary to feel shortness of breath or a sense of oxygen deprivation in order for the body to be dangerously short of oxygen. The sensation of being unable to breathe comes as a result of unusually high levels of carbon dioxide (CO2) rather than low levels of oxygen. Because of this, people who inhale pure nitrous oxide or other gases do not have the sensation of being unable to breathe, despite not getting enough (or any) oxygen. It is quite possible to suffocate while breathing pure nitrous oxide without ever feeling discomfort or a shortness of breath.
  
  
  • Never strap a gas mask to your face while using pure nitrous as it is possible to black out and die from lack of oxygen.
  • Never use a garbage bag as a delivery device. It is possible (and has happened) to black out and suffocate when the bag falls over the nose and mouth.
  • Never open a tank of nitrous in a sealed room, closet, car, or other space.
  
  
• Very cold temperatures of the gas can freeze the lips and throat if taken directly from a tank or whippit. Releasing the gas into a balloon first allows the gas to warm before being administered.
  
  
• High levels of pressure may rupture blood vessels in the lungs and force air into the chest cavity, causing the lungs to collapse. This is primarily a problem when nitrous is being administered directly from a tank or other pressurized container. Again, releasing the gas into a balloon first eliminates this risk.
  
  
• Heavy and frequent nitrous use can deplete vitamin B12 in the body and lead to serious and unpleasant neurological problems. Users may experience numbness and tingling in the fingers, toes, lips, etc. In more severe cases, numbness of all extremeties. Taking B12 supplements, especially in combination with multi vitamin and complete amino acid supplements, may help alleviate this problem. If you experience these symptoms, cease nitrous use immediately and if the symptoms persist, seek medical attention. See Nitrous & B-Vitamin Dangers.
  
  
• Careless use of nitrous oxide can also cause nausea, vomiting, and disorientation, primarily from inhaling too much, too soon.
  
  
• Since nitrous produces a temporary loss of motor control and dissociation, it's extremely unwise to inhale it while standing or while in any situation where unconsciousness is dangerous.
  
  
• Some users of nitrous report headaches and generalized discomfort for an hour or more after inhalation.
  
  
• Nitric Oxide, a toxic industrial gas, is occasionally mistaken for Nitrous Oxide. Users should be careful they know what they are inhaling. Inhaling Nitric Oxide can permanently damage the lungs or kill.



• Olney's Lesions: there is little to no evidence that Nitrous Oxide use causes the brain lesions described in William White's "This is your Brain on Dissociatives" and, without further evidence, this hypothesis should be considered invalid for Nitrous Oxide.