Studies suggest that teenagers aren't getting enough sleep. Being glued to their mobiles, tablets and other screens may be one reason why.
Just over half of 11 to 17 year olds say they are getting eight or more hours' sleep a night. Sleep experts say young people in this age group tend to need at least eight hours' sleep to concentrate at school and to maintain their health and wellbeing.
They reckon that screens and other electronic devices are to blame and advise placing strict limits on the use of TVs, mobile phones or computers in a child's bedroom during the evening. The light from screens can affect how easily children get to sleep, and gadgets can be a constant distraction, stopping children getting the rest they need.
Children need deep sleep
Professor Jim Horne of Loughborough University's Sleep Research Centre is an expert in sleep deprivation and says children going through puberty and adolescence need to "sleep longer and deeper".
"It's a time during which their brains are undergoing major change," he says. "The brain is undergoing major restructuring and rewiring, and sleep is important for it to recover.
"A poor night's sleep can interfere with a child's performance and behaviour the following day. There's a stereotype of teenagers being grumpy and bad-tempered, and that's sometimes due to a lack of sleep."
"Bedrooms are changing from a place of rest and tranquillity to places where there are lots of things to keep children awake, such as computers and televisions," says Horne.
"Children are often tempted to take their mobile phone to bed with them and start texting without their mum and dad knowing.
"This distraction means they're not in a relaxed state for good-quality sleep, which can affect their learning.
"I would place firm night-time limits on the use of a television, mobile phone or a computer in their bedroom."
Article provided by NHS Choices