West Yorkshire Police say they are seeing a rise in cases of young people with bladder problems because of the drug ketamine.
The drug damages the cells lining the bladder, reducing bladder capacity.
Signs of bladder irritation include sudden urges to pass urine, needing to pass urine more frequently - in the most serious cases every few minutes- pain, incontinence and blood in urine.
More and more people are suffering from Ketamine Bladder Syndrome, with a new case appearing in Leeds every three to four months.
The police and health services are urging people to consider the dangers of legal and illegal highs on their health.
They say the number of people being arrested in West Yorkshire for possessing methedrone and ketamine is going up.
In 2010, 123 people are arrested for possessing methedrone. That number increased to 173 in 2011, and so far in 2012 there have been 183 arrests made.
In 2010, 33 people were arrested for possessing ketamine, which increased to 41 in 2011 and so far this year there have been 19 arrests made.
This week a report from the National Programme on Substance Abuse Deaths identified that of the 1,833 deaths in the UK during 2010, 29 of these were from Mephedrone.
West Yorkshire Police’s drugs co-ordinator Bryan Dent said: “We know that youngsters are opting to take new psychoative substances over other drugs such as heroin and crack cocaine, but have no idea of the dangers they pose to them especially when consumed with alcohol.
“As these substances have only been around for the last few years research is still being done to look at the short-term as well as the long-term effects it can have on the health of users as well as potentially gaining themselves a criminal record.
“Young people are playing russian roulette with their lives and it has an impact on public services, including the police often initially attending the incident of a young person acting in a strange manner or aggressively or where they have just collapsed.
“It impacts on the ambulance service attending, which then often impacts on the A and E department and thereafter on drug treatment agencies, not to mention, schools, work environment and of course the persons family.”
If you know of anyone dealing or supplying ketamine, mephedrone or other type of illegal drug, you can ring Crime Stoppers anonymously on 0800 555111.