We can't live without it, but it’s thought a third of us in the UK are simply not getting enough quality sleep. In fact, the problem has become so serious, it's been described as a 'major public health concern'.
Tonight's Fiona Foster meets people whose lives have become dominated by bad sleep, and investigates the causes and possible solutions.
So have we now become a nation of bad sleepers, and what should be done about it? Some experts believe that sleep has been left off of the agenda for too long.
Rhianwen Gilmore from South Wales has suffered from night terrors for five years. She gets terrifying visions during the early stages of sleep, and wakes up screaming.
Using night vision cameras Tonight captured evidence of Rhianwen's night terrors for a hospital to analyse, and hopefully treat.
Sleeping trouble is now the most widely reported psychological disorder in the UK. It's estimated that around twenty million of us could be suffering , affecting our personal lives and our performance at work.
Greg Shilton from Wednesbury in the West Midlands first developed sleep issues as a child, but what he had always thought of as just noisy snoring, was the symptom of a life threatening issue. Greg had severe sleep apnoea, and was stopping breathing 80 times an hour. He now uses a mask to keep his airway open whilst he sleeps.
With research suggesting that one in five teenagers have disturbed sleep due to technology, the problem is unlikely to go away, so how do we solve the problem of getting a good night’s sleep?
Why Can’t We Sleep?: Tonight is on ITV this evening at 7.30