The calming inhalant known as laughing gas is for patients who are mildly or moderately anxious or nervous. It eases their anxieties so that they can relax and undergo treatment comfortably and safely. The gas is administered by placing a small hood over the patient's nose. As the gas takes effect, the patient becomes relaxed, but is still awake and can communicate. When the gas is turned off, the effects of sedation wear off almost immediately.