World Sleep Day: How much sleep people need depending on how old they are

You probably did not get the right amount of sleep you needed as a teenager

Sleeping like a baby (Getty istock)

Many of us are not getting the right amount of sleep we need. From long hours at demanding jobs, late night Instagram-scrolling and stress-induced insomnia, sleep sometimes becomes a long way down our list of priorities.

The phenomenon was even dubbed a ‘sleep crisis’ by researchers in the United States last year. Earlier this year, a report suggested the UK loses $50billion (£40.4 billion) and 604,000 working days a year due to sleep deprivation whereas the US loses $411 billion. In 2014, it was estimated six out of 10 British people are sleep deprived, partly because of the advent of smart phones.

But how much sleep do you actually need? There has long been an association with successful people such as heads of government, CEOs and business moguls who have spoken about functioning at a particularly high level on just a few hours of sleep each night.

The amount of sleep we need varies on many factors, one of which is our age. Ana Noia, a senior clinical physiologist in neurophysiology and sleep, at Bupa Cromwell Hospital told The Independent that while how much sleep someone needs can vary according to the individual, as a standard rule how much sleep someone needs will change with age.

According to Noia:

• Newborns need 16-18 hours a day,
• Two-year-olds typically need on average 11-13 hours. 
• By the age of five, children will sleep between 10-12 hours. 
• Teenagers definitely don’t sleep enough and should be getting eight to 10 hours.
• From the age of 20 onwards it is normal to sleep seven to nine hours.
• Once you’re older than 65, the amount of sleep you need actually decreases, to around five to seven hours. However, she recommends that adults sleep between seven to eight hours a night.

Why we need to rest our eyes for different amounts of time depending on our age comes down to the complex changes in how the brain develops, our circadian rhythm, environmental factors, work and social needs and demands according to Noia.

For instance, the vast amount of sleep children require is because the hormone melatonin, which helps us sleep, reaches its peak at around seven or eight years old. This begins decreasing during the mid teen years until the age of 70 when it is essentially non-existent in our bodies, meaning the need for sleep decreases. Additionally, elderly people are likely to find their quality of sleep is worse than when they were younger because sleep becomes more fragmented and not as deep as you age.

“The most dramatic change occurs in the elderly. Deep sleep, for example, can almost disappear,” Noia says.

The phrase sleeping like a baby is clearly exemplified by the fact they are sometimes only awake for just six hours a day. The reason why they sleep so much is because it is vital for acquiring and consolidating memories, learning and for brain development, says Noia.

“During sleep, the hormone which stimulates growth, cell reproduction and regeneration is also released, so you can see why little ones sleep so much,” she says.

Whatever a person’s age, sleep is key for good health and wellbeing. The effects of poor sleep have been linked to obesity, depression, poor memory, heart disease, diabetes and high blood pressure.

However, for those acutely aware they are not getting enough sleep, they may, in turn, be pressurising themselves which Noia says can also be detrimental.

“People who find it difficult falling asleep often ‘make sleep a priority’. They schedule everything they do, minute by minute, which can be very stressful and actually hinder good quality sleep itself.

"The worry of not falling asleep in a ‘schedule’ can bring bedtime tension and excessive worrying about not falling asleep at the right time. People should only go to bed if they feel they are ready to sleep."