'I spent 18 hours a day watching YouTube'
Newsround has been to a special camp in South Korea for teenagers who are addicted to the internet and their smartphones.
Official figures show that thousands of young people there are affected by the problem.
At the camp, we met Hawon who is taking steps to deal with her addiction to YouTube.
"I watch YouTube literally every single day, sometimes for 18 hours," she said.
Watch the video and read our guide to find out more.