Laughing gas is nitrous oxide, a colorless, odorless gas used in medicine for pain relief, sedation, and as an add-on to general anesthesia. It is also used in dentistry and for labor pain. It can make people feel relaxed or euphoric, which is why it got the nickname “laughing gas.”

Nitrous oxide is breathed in through a mask or other breathing device. It works fast, usually within 2 to 5 minutes, and it wears off quickly too. It is a weak anesthetic by itself, so it is usually mixed with oxygen and sometimes other anesthetic drugs. It should never be given without oxygen.

It helps by blocking certain brain signals and by boosting the body’s own pain control pathways. It can also expand air-filled spaces in the body, and it can affect vitamin B12 activity. Because of that, repeated exposure can cause nerve or blood problems.