The number of teenagers who have self-harmed has tripled in the last decade in England, a new survey suggests.

The Health Behaviour in School-Aged Children (HBSC) report reveals that 20% of the 15-year-olds questioned had hurt themselves in the previous year.

The study, produced along with the World Health Organisation, spoke to 6,000 people in England aged 11, 13 and 15 and is due out later this year.

Self-harm can include biting and burning, as well as cutting oneself.

For further detailson Self Harming visit our pages at http://www.asknormen.co.uk/cutting-self-harm/

Prof Fiona Brooks, head of adolescent and child health at the University of Hertfordshire, led the HBSC investigation.

"Our findings are really worrying, and it [self-harm] is considerably worse among girls," 

"At age 11, both girls and boys report a good level of emotional wellbeing. But by the age of 15, the gap has widened and we get 45% of adolescent girls saying they feel low once a week compared with 23% of boys."

She said factors such as stress at home, pressure to get the grades for university and the lack of a "guarantee of a job at the end of it all" can all contribute to poor mental health.

She said young people are "turning to strategies such as self-harm to manage stress in the short term".

Last year The National Institute for Health and Care Excellence published new guidance to improve standards of care for people who had self-harmed.

It claimed judgemental and negative attitudes by some hospital staff can result in some patients going on to deliberately harm themselves again.

NICE said around 220,000 people who self-harm are treated in hospital in England every year.

The Royal College of Psychiatrists says the rate of self-harm has continued to rise in the UK over the past 20 years.

NICE says it hopes better medical assessments will reduce the number of hospital admissions for self-harm.