A young woman from Bristol has been left unable to walk after inhaling laughing gas.
Olivia Golding took nitrous oxide at a festival but tests have found it has damaged the top of her spinal cord and nervous system.
This can be a rare side effect of using the drug.
Last month the 24-year-old was fit and healthy, but after being admitted to Southmead Hospital two weeks ago, doctors do not know yet if she'll make a full recovery.
Olivia's now warning others of the dangers of breathing in nitrous oxide gas through a balloon, saying a 20 second high is not worth the months of rehabilitation.
According to the NHS nitrous oxide is a gas with several legitimate uses, but when inhaled it can make people feel euphoric and relaxed.
However, there is a risk of death as a lack of oxygen can occur when using nitrous oxide.