By Denise Winterman BBC News Magazine

Ask someone how they are and their response, more often than not, is "fine but a bit tired". Not surprising when one in three of us have sleep problems, according to recent research.

The medical profession calls it tatt, short for "tired all the time". It's one of the most common complaints that doctors hear. The disappearance of rest from daily life is also one of the themes of a major new exhibition on sleep at the Wellcome Collection in London.

Sleep is no longer a priority

We just aren't getting enough sleep and it's slipping down people's list of priorities. It seems modern life is just too demanding - and exciting - to switch off.

As a result sleep deprivation is becoming a national problem, say experts.

Sleep is so important because it allows the brain to recover from the rigours of the day. Not getting enough has been found to increase the risk of obesity, heart disease and depression. The government is keen to tackle these health issues, efforts doomed to failure unless getting enough sleep is made a priority as well.

"Sleep is as important as diet and exercise when it comes to the nation's health," says Doctor Neil Stanley, a sleep expert at the Norfolk and Norwich University Hospital.

"But we place no importance on it in our culture. When you are sleep deprived you are putting yourself in a stress situation. In our culture it is socially acceptable to have had no sleep and go into work, even though your ability to function is severely impaired and you could be dangerous."

But even if you cut back on the late nights, how to tackle the problem of falling asleep? Here are some tips:

Tensing until your muscles hurt may not seem the most sensible way of getting to sleep, but it's a popular and proven cognitive technique.

Get tense to relax

Progressive Muscle Relaxation (PMR) is about exaggerating the feeling of relaxation to help the mind and body wind down.

Systematically tense each muscle group in turn until it starts to hurt - about 20 seconds - and then let go. This creates a warm feeling of relaxation, and any tension should flow away. The theory is that with physical relaxation comes mental calmness. PMR is used as a stress buster, as well as helping sleep.

"It promotes sleep because it is like a meditation," says Professor Kevin Morgan, director of the Clinical Sleep Research Unit at Loughborough University. "It's a very clever technique and is a strategy that is evidence-based and rational."

It sounds simple, but experts say it's important to be taught how to do PMR properly. Once instructed, practice the technique each day, in the same environment. The more you do, the more you will be able to do it in other conditions and with distractions.

The key to falling sleep is all about relaxing the mind and the body. Much of what we do to wind down may relax the body, but the mind is still ticking over.

TV watching doesn't relax the mind

"Your mind spends the working day remembering and placing names and faces and all the information that goes a long with it," says Dr Stanley.

"Sitting down and watching EastEnders might relax the body but the mind is still working, remembering who the characters are and what they do. It might all be rubbish, but it's still keeping the mind ticking over."

The key is to use something to relax that requires no mental thought process at all.

He suggests dusting down old and familiar CDs - new music is no good as you end up concentrating on the lyrics.

"You know old albums inside out and don't have to concentrate. They become pleasant background music."

We've all been there - in bed, desperate for sleep but unable to switch off the thoughts running through our heads. Work, family, debt... all keep us awake at some point in our lives.

Just repeating "the" could be the solution. It's known as a blocking strategy, another cognitive technique. The aim is to stop the mind racing.

Repeating a simple word like "the" at irregular interval blocks other thoughts coming into your head.

"If you say the word at regular intervals, you stop thinking about what you are saying and other thought come back in," says Professor Morgan.

"By saying the word at irregular intervals, you make sure you are just monitoring what you are saying."

Popular in the 1980s, power naps have a fast and effective restorative power that is hard to beat.

Power naps are better than coffee

"A 20-minute nap gives you an amazing boost, it's much better than having a coffee," says Dr Stanley. "Even closing your eyes for 20 minutes is better than nothing.

"But in the UK it is culturally unacceptable for us to be found napping with our head on the keyboard. However, it's fine to pump yourself with caffeine even though it it's nowhere near as effective."

Dr Stanley says having a nap during the day should not be used to replace sleep at night, but other researchers suggest that it could do you as much good as seven hours sleep at night.

American sleep expert Doctor Sara Mednick describes taking a regular nap as a "lifesaving habit" that can help improve your health and sex life, slim the waist and boost work performance.

Napping at work isn't acceptable in the UK, but in Japan dozing anywhere from Parliament to business meetings is allowed. It's called inemuri, which literally means "to be asleep while present".

Japan's ex-prime minister shows how it's done

The custom is partly a result of how commitment to a job is judged in Japan, says Dr Brigitte Steger. Inemuri is viewed as exhaustion from working hard and sacrificing sleep at night. Many people fake it to look committed to their job.

It's a concept that seems bizarre in the UK but the Japanese are the ones who've got it right, says Dr Stanley.

"The Japanese are right in their assessment that you work better after a nap than before it. There's a degree of machismo about it, you're saying look how hard I've worked. But that's better than the macho rituals we have over here, like how late you can send a work email to prove how long you've been working."

Strict rules apply to inemuri. These include who is allowed to do it - only those high up or low down in a company - and how you do it - remain upright to show you are still socially engaged in some way.

"The rules are written nowhere but everyone knows them, they learn them culturally," says Dr Steger.

Add your comments on this story, using the form below.

The East Asians do seem more enlightened when it comes to the benefits of sleep. Here in Korea many companies turn the lights off at lunchtime so people can take a nap.
Mel Buckpitt, Seoul, South Korea

I could not get thru the day if it were not for my afternoon nap; sometimes 30 mins or even an hour. I awake refreshed and clear and ready for a beer.
Andrew Ferm, Kansas City, Missouri

Over here in Japan I was shocked by how many people just sleep anywhere. Starbucks and McDonalds at lunchtimes seem to be favourites, but pretty much anywhere - standing up next to a vending machine was the funniest I've seen. But now I've been here a while, I've developed the habit myself - although I do have to set my mobile phone alarm to wake up at the right time so I don't miss my train stop (the Japanese have this built in it seems).
Allan Connell, Kitakyushu, Japan

I used to work in a bank, often doing long hours and there were periods during that day when I achieved nothing because I was knackered. I then came across a company in the US - MetroNaps - that specialises in mid-day napping solutions for companies. I never looked back and took on the UK licence. I also now nap regularly and achieve a great deal more as a result. The old excuse in Britain that I'm too busy to work is hugely counterproductive. When you can achieve 34% more post-nap (Nasa findings) you cut the time in the office and the quality of the output of work. People are starting to wake up to napping.
Marcus de Guingand, London, UK

I listen to audiobooks to help me nod off at night. Rather than dwell over any problems and allow them to snowball, I just listen to the story. However, I'm not sure Stephen Fry would be too impressed at the fact that listening to him read Harry Potter helps me fall asleep!
Nicola Burden, Wimbledon, UK

Being Italian I like the way Italy & a few other European nations do it when it comes to work. In Italy the traditional way in various retail stores & shops is that you work from 9am to 1pm & then the shop closes for 3-4 hrs & then work til 8pm. In those 3/4 hrs you go home & you either sleep, do housework, do the shopping or even the younger workers would meet up with their friends & go to a cafe or bar. This is more of a village or town job where I come from; the big cities have different ways but this was always the more social option.
Claudio, Glasgow

I'd like to know where to find one of these doctors that will actually discuss sleep issues with you - I've had problems with sleep disorders for the best part of a decade, and all I can get from my GP is to practice "sleep hygiene" (go to bed early) and abstain from coffee - which given that I never touch the stuff is not particularly useful. To paraphrase (slightly) an old record: "There is no rest for the wicked ones, but what have I done?"
Eddie, Edinburgh

A few years ago I got in to the habit of falling asleep on the train going home. It was about a half hour nap and always made me refreshed and energised to work on through the evening at my second job. The only problem is that now my body is programmed to shut down around 5pm for a sleep. Even if I've had a good nights sleep the night before.
Matt, London, UK

I find playing the A-Z game helps me fall asleep. When in bed close your eyes and pick a subject - fruit, pop stars, chemist shop etc - and name items in that category from A to Z . I never make it to Z as I'm Zzzzzzzzzz.
Helen, Bracknell

Nothing does it for me quite like watching the BBC News...
John R Green, Stoke on Trent

Last year at uni, I used to get the bus in in the mornings and home in the evenings - the 30min journey provided the perfect opportunity for a nap, and I always woke up about 30 seconds before I got to my stop. An awesome refresher after an early start and then a hard day!
Neil Munday, Southampton

Since mid-teens, I have had the ability to sleep in any location in mostly any position. Makes it great for long haul flights in economy and all the taxi rides when travelling and going to another company office, but it does mean I have to concentrate really hard in meetings otherwise the inevitable can happen. Oh for a siesta culture in the company...
Ben E, Mexico City

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