A SPECIALIST doctor believes it is only a matter of time before more people die from taking so-called legal highs, as a survey showed the number of young people needing emergency treatment after taking them has more than trebled in a year.

Patients who take the substances are often so seriously ill when they come to hospital that urgent specialist treatment is needed, said Dr Richard Stevenson of Glasgow Royal Infirmary.

"When these patients arrive we can only treat the symptoms, because we don't know what they have taken –and neither do they," said the senior speciality doctor in emergency medicine.

"The symptoms are a very fast heartbeat, high blood pressure and muscles beginning to break down, leading to a very high risk of having a stroke or heart attack.

"They also have very altered perception, which can be very dangerous and makes it difficult to help or treat them.

"None of the cases admitted this year have died, but no-one should be under any misapprehension that legal highs are potential killers. If this steep rise in admissions continue, it is only a matter of time until we see deaths."

The hospitals surveyed were Glasgow's Western Infirmary, Inverclyde Royal, Vale of Leven and two of the country's busiest accident and emergency units at Paisley's Royal Alexandra hospital and Glasgow Royal Infirmary.

Dr Stevenson said: "Many of those patients we see and talk to do not regard themselves as drug users – they seem to think there is less risk with so-called legal highs which they regard as recreational drugs.

"The medical teams who treat them see all too often how dangerous and lethal these chemicals really are."

Earlier this month, police called for the power to seize legal highs following the death of a teenager at the RockNess music festival in June.

Alex Heriot, 19, from Edinburgh, is said to have taken Benzo Fury, a drug easily found for sale on the internet.