More than one-third of young people surveyed by a Dundee charity claimed to have been affected by the distribution of explicit texts, images or videos, leading to calls from health professionals for a new strategy to combat the risks of "sexting".

The Corner, which offers health information and peer-led support for young people, carried out the research at the end of last year as part of a campaign to raise awareness of the problems sexting can cause, and to allow workers to get an idea of its scale.

More than 200 young people took part, of whom 85 said they, or a friend, had been affected by sexting, while 121 said they had not.

These included 34 of the 100 under-16s spoken to, and 27 out of 67 (40%) of under-20s.

The survey asked what sexting meant to young people, with 11 saying it meant sending naked pictures by text, four said it meant sending semi-naked pictures via instant messaging or Blackberry messages, and 14 said it meant having a sexual conversation via text, instant messaging or using Facebook. The vast majority – 177 young people (86%) – answered "all of the above".

Asked whether they could get in trouble legally for sexting, 72% of young people thought they could.

Over the course of two months the Corner ran a window display about the topic along the theme of "Pose, sext, what happens next?" and distributed a booklet pointing out to young people there can be serious legal consequences for distributing explicit pictures or videos of minors, as well as raising the issue of other problems such as the risk of affecting future employment prospects.

Jackie Fitzpatrick, sexual health nurse at the Corner, said the issue was constantly prominent in the media during the campaign, from the high profile sex tape distributed against the wishes of X Factor star Tulisa Contostavlos, to the students at Exeter University whose activities at a safe-sex ball were filmed and distributed recently without their knowledge.

Earlier this month, former Spice Girl Geri Halliwell filmed herself in the recording studio after stripping down to her bra. Ms Fitzpatrick said: "If Geri Halliwell does it aged 40, why can't a teenager do it to her boyfriend?

"We see a lot of girls who are put under pressure to send photos to their boyfriends and a lot of lads don't understand the impact it is having on the girls. Finally a girl will give in and send the picture and she's in the wrong, not him. The boys will say, 'Well she sent me the picture.'"

The Corner regularly has awareness campaigns but this has been one of the most talked about, according to Ms Fitzpatrick. "A lot of young people wanted to talk about this and the impact it has had on them and their friends.

"Technology has lots of benefits, but people need to be aware of the downside too. What you put on the internet is there forever, and I don't think young people are 100% aware of that. There is an ignorance and naivety among young people and even more among parents."

Shelley McBride, an NHS Tayside midwife who also works at the Corner, said many teenage girls did not see the demands of boyfriends as coercion, but added: "Some of them don't see it like that until you talk to them, but later they look at it a bit differently."

The campaign had considerably raised workers' own awareness of the issue, Ms McBride added. "Other agencies also say they are seeing it all the time," she said. "I think there needs to be something more strategic to look at this issue because it is becoming quite concerning."

The campaign has already attracted inquiries from further afield and the Corner is now in discussions with a mental health charity which is considering carrying out similar research in Fife.