The gas is widely used in medicine as a pain reliever, or anesthetic, and to reduce anxiety.
Nitrous oxide also has many industrial uses and chefs even use it to make cream.
But it's the use of gas for recreation that is causing concern.
It can cause hallucinations of sound distortion and heart problems in people with high blood pressure and when inhaled, it presses on the lungs which can cause breathing problems.
There are laws aimed at stopping drug abuse in the UK, but some shops still sell nitrous oxide illegally.
