It could be the video games you play at night to unwind. Dr. Michael Grandner is with the University of Pennsylvania’s Sleep Medicine Program. He says the blue light from screens will disturb your sleep. But so can intense, interactive video games – like Call of Duty! They stimulate the brain, and boost production of stress hormones – making it nearly impossible to wind down and drift off. And by the way, nearly half of all gamers are women – it’s not just a guy thing. Bottom line: If you’re having trouble sleeping, you may want to cut yourself off from gaming at least an hour before bed.