Getting less than six hours sleep a night increases risk of early death, The Independent

Not sleeping releases hormones that increase stress levels, speed up the heart rate and raise blood pressure

Less Than Six Hours of Sleep Could Lead to Early Death, Says New Research

Lack of Sleep May Lead to Early Death, Study Finds

Regular lack of sleep is 'linked to early death', The Independent

Sleeping between 7 and 9 hours a night can slash risk of early death

Too little sleep could kill you: Premature death risk goes up for those who get less than 6 hours – New York Daily News

Dream ticket: how sleep became a billion-dollar business, Sleep

Sleeping for more than eight hours each night increases risk of early death, study finds, London Evening Standard

Poor sleep linked to dementia and early death, study finds

Poor sleep linked to dementia and early death, study finds

IJERPH, Free Full-Text

Adults who sleep less than six hours a night are at higher risk for dementia

Six to 8 Hours a Night May Be the Sweet Spot for Sleep - The New York Times