Whenever you can't sleep, it is possible that your brain is whirring about bills, locked doors, meetings, issues in the office, plus the mobile phone lying beside you or on top of the bedside table.

Experts say sleeping with our mobile phone beside us makes us hypervigilant, it disturbs sleep and prevents us from sleeping again. It will promote sleeping problems and insomnia. If the bedroom is free from electronic devices and mobile phones, people will sleep better. It is suggested that devices and mobile phones should be left outside the room. Other effects of sleeping with mobile phone beside the bed are headaches and dizziness.

Light is the main issue with mobile phones in the bedroom, specifically the type that is created by high quality and big screen of smart phones. About four in ten mobile phones, particularly smart phones users state they check their phones in the middle of night. They grab it to check if they have important messages, interesting news on social media and sometimes play their favorite games. This is according to the study at Sheffield University in cognitive and psychology science.

Based on the study of Dr. Orfeu Buxton, "This has a powerful effect - even more than when we know for certain there will be something rewarding. So we want to check our phone more often than we rationally know we should - just in case.' This ties in with what Harvard neuroscientist Dr Orfeu Buxton has described as 'threat vigilance' - because we're never truly relaxed when our mobile is by the bed, we struggle to sleep properly.

He suggested that, in order to a deep and restful sleep, they should not worry about anything and should feel safe. Mobile phones should be turned off at night, because the subconscious would want to check it all the time.