What's the problem?

Lack of sleep has a huge impact on economies, on people's health and on their happiness.

But all too often in the past, sleep has been treated as a fact of life rather than as a major public health issue that deserves more attention.

That looks like it might be changing, with governments in many parts of the world involved in studies to try to measure the impact lack of sleep has and the options for changing the situation.

How much sleep should you get?

The widely recommended nightly amount of sleep is between seven hours and nine hours.

Everybody is different, so some people need more than others. But if people regularly get six hours or less, experts say that has an impact on their health and on society.

Why do people not get enough sleep?

"If you have really high job demands, a lot of stress, long working hours and feel obliged to check your work emails just before sleep that has negative consequences for sleeping well at night," says Marco Hafner, head of research at RAND Europe.

"You also find that if you have really long commutes to work, that has a negative effect on your sleep duration – mainly because you probably have to get up early in the morning to get to work and then also have a long commute to come back home and you will still have activities after work, so that will delay your bedtime," says Hafner.

Then there are things that are easier for everyone to control – one is the idea of a glass of wine or other nightcap to help someone get to sleep: "There is a lot of research showing that drinking alcohol before bedtime has a negative effect on sleep quality," he adds.

The blue light from phones and laptops may also have an impact on the production of your sleep hormone melatonin, says Hafner, so screen time immediately before trying to go to sleep might not be a good idea.

There are many reasons why people might not sleep well, but some of the others include not getting enough exercise, smoking and having a high body mass index (BMI) – although it is not clear if that is a cause of not sleeping well, or an effect of not sleeping well.

Why does it matter if you don't sleep enough?

Economic

The cost to the world's larger economies was estimated to be hundreds of billions of dollars per year in a study by RAND Europe, based on the proportions of workers in each country regularly sleeping for less than seven hours a night:

- U.S. $411bn (2.28 percent of GDP, based on 2015 figures)

- Japan $138bn (2.9 percent of GDP)

- Germany $60bn (1.56 percent of GDP)

- UK $50bn (1.56 percent of GDP)

- Canada $21.4bn (1.38 percent of GDP)

According to Hafner "People who don't sleep enough are more likely to be absent from work.

"Those who go to work are not as productive as they could be and that subsequently has a negative knock-on effect on their colleagues.

"If they don't deliver the work they have to it has a negative effect on the company. And if the company doesn't do that well and it hurts the bottom line, that subsequently, on aggregate, has a negative effect overall on the country's GDP."

On a longer-term level, a higher death rate and more demands on the health service are also a negative for a country's economy – as is the impact on school children who might not develop as quickly or as well, if they do not get enough good-quality sleep.

Accidents

There is a growing amount of evidence that people are more likely to have accidents at work if they have not had a good night's sleep.

Hafner says: "There's research showing that if you don't sleep enough, you are more likely have a car accident – almost to the same level as driving under the influence of alcohol.

"People often think 'I shouldn't drive a car when under the influence of alcohol,' but actually, if you didn't have a good night's sleep potentially you put yourself equally at risk."

The UK's Royal Society for the Prevention of Accidents suggests that driver fatigue may be a contributory factor in up to 20 percent of all road accidents and up to one-quarter of fatal and serious ones.

Health

The occasional night of bad sleep, or interrupted sleep, might make you tired and irritable, but is not thought to have a long-term impact on health. 

If it continues, the UK's National Health Service (NHS) warns, after a few days "the mental effects become more serious – your brain will fog, making it difficult to concentrate and make decisions. You may start to feel down and may fall asleep during the day."

The NHS warns that your chances of injury in accidents increases and, if the lack of sleep continues, it can "affect your overall health and make you prone to serious medical conditions such as obesity, heart disease, high blood pressure and diabetes."

It also suggests people who sleep less have a higher chance of putting on weight and that lack of sleep can harm the immune system and mean you are less likely to be able to fend off bugs.

Extended periods of too little sleep can also lead "to long-term mood disorders like depression and anxiety."

Top tips for getting better sleep

As the NHS advice puts it: "If you don't get enough sleep, there's only way to compensate – getting more sleep."

Have a regular wake-up time: Try to wake up at the same time every day, rather than lying in to try to "catch up" on lost sleep the previous day or during the week. This means the brain and body clock get used to the routine.

Limit the use of electronic devices before bedtime: The blue light from screens is thought to suppress people's melatonin levels, a hormone vital for sleep and waking cycles, says Hafner.

Avoid stressful issues just before bedtime: Research studies suggest that setting aside time earlier in the day to tackle stressful issues can help people sleep better.

Exercise and fresh air: There is a lot of research showing that exercise has been associated with improved sleep outcomes. Although going for a run straight before bedtime is not recommended.

Wind down: A warm bath can help your body reach an ideal temperature for rest, writing a "to do" list for the next day can organize thoughts and clear your mind of distractions from sleep. Reading a book or listening to the radio relaxes the mind by distracting it, says the NHS guide.

Further reading:

Get more sleep: Chinese students are getting less sleep

Bedtimes in China are two hours later because of pandemic

Sleep aids: Can they help the 300m Chinese with sleep disorders?