Children aged four in Wales' A&Es for drink and drugs
Children as young as four have been treated in accident and emergency departments in Wales for the effects of alcohol, research shows.
Figures obtained by BBC Wales suggest at least 1,200 children attend casualty each year because of drink and drugs.
Children under 12 are among cases of alcohol and drug poisoning.
Dr Richard Lewis, Welsh secretary of the British Medical Association, said the issue was "increasingly worrying".
"I think it's pretty well recognised by health services and health professionals that there's an increasing problem with both alcohol and drug-related incidents with younger and younger people," said Dr Lewis.
"We see year-on-year increases with attendances at A&E departments, particularly for alcohol."
One young person in casualty as a result of alcohol and drugs was one too many, he said.
"It is increasingly worrying. The BMA and the health profession have been advancing for some time the importance of raising the awareness of alcohol in particular," he added.
The figures, obtained through a Freedom of Information request, show that more than 800 children have attended casualty in each of the past three years in cases where alcohol is a factor.
Hundreds more have been seen after taking drugs, although figures are not necessarily for substance abuse as they may include incidents such as an accidental swallowing of tablets or medication overdose.
Clive Wolfendale, chief executive of north Wales drug and alcohol agency Cais, said the problem of children regularly drinking to such extremes had taken off around five years ago.
"Where kids go first for what might be described as a high is drink, rather than cannabis or opiates or ecstasy or legal highs. The substance of choice is alcohol," he said.
"The reasons for that are two-fold. First of all it's the cheapness and availability because, in real terms, it's cheaper that it's ever been."
The former North Wales Police deputy chief constable said efforts to prevent the sale of alcohol to children was "easily circumvented" by older people buying it on their behalf.
"The second reason [for alcohol's popularity] is the general thrust of marketing," he added.
"The drink companies are on social networking sites and there's still a lot of direct advertising going on through sports sponsorship and so on.
"It's perceived as a cool thing to do. That's why young people are much more likely to end up in casualty requiring a stomach pump and so on."
Welsh Government guidance states that children under 15 should not drink alcohol as there is evidence that it can harm the developing brain, bones and hormones. It also warns that drinking at 15 and older can be hazardous to health.
Aneurin Bevan Health Board, a small board which covers the former Gwent area, said the vast majority of cases contained in its figures related to teenage alcohol intoxication and misuse.
However, the health board has also dealt with 21 cases of actual alcohol poisoning among children since 2006, including six for children aged 11 and under.
It has also treated 39 children for drug poisoning from narcotics/hallucinogens since 2006, including 10 last year.
Larger health boards such as Abertawe Bro Morgannwg, which serves Swansea, Bridgend and Neath Port Talbot, Cardiff and Vale, and Betsi Cadwaladr, which covers north Wales, each treat hundreds of children every year in their casualty departments for the effects of drink and drugs.
Children's Commissioner for Wales, Keith Towler, said the figures did not come as a surprise.
"The Welsh Government published its latest wellbeing monitor earlier this year which highlighted how people aged under 20 account for almost one in 10 of all referrals for treatment for alcohol problems in Wales," he said.
"The long-term dangers of alcohol and drug misuse are well documented, and more and more young people now understand the health risks associated with excessive drinking and are, in fact, choosing to avoid alcohol.
"But if we want to successfully combat this problem I think we need to shift society's general attitudes towards alcohol.
"There is plenty of information out there to help children and young people make informed decisions but children tend to succumb to peer pressure and often model the behaviour of those around them.
"Whilst educating children and young people must remain a top priority, there is also a need for adults involved in a child's life to take responsibility."
Welsh Government figures for 2008-09 showed that more than 120 children under the age of 12 in Wales were referred for specialist help for drug and alcohol problems.
Figures between health boards may not be directly comparable as differing methods of compiling data have been used.