Charity wants more help for teenage runaways
5 February 2013 Last updated at 08:11 GMT
It is estimated that tens of thousands of children run away from their homes every year and put themselves in danger by living on the streets.
Now, a new report by the Railway Children charity says more needs to be done to help young people who feel they have no choice but to run away.
Chris Buckler reports from Sheffield, where he has been finding out more about why so many under-18s go missing.