By Helen Foster

Jemma Harrison sighs. 'The night before last I had two hours sleep,' says the 31-year-old who runs a hat business. 'That's extreme, but I'll often wake in the middle of the night, thinking of something work-related.

'Because I usually take work into my bedroom, I often find myself turning the computer back on to check things are ok. Some nights it can take me four hours to get back to sleep.'

A shocking one-in-three Britons now suffer sleep problems, and hormonal issues mean women are plagued by insomnia more than men. But experts are beginning to put special focus on a newly identified sleep disorder called 'semi-somnia', which is claiming growing numbers of sufferers.

It's been called insomnia's irritating little sister, but despite not sharing the full agonising symptoms of acute sleeplessness - which has been linked to weakened immune systems, depression, high blood pressure and even heart disease - semi-somnia is far from harmless.

Rather than totally sleepless nights, sufferers experience short bouts of sleep disruption - perhaps on particularly busy or stressful days. They may wake every night for 30 minutes, or find it impossible to sleep for an hour because their minds are racing

Then there's 'fizzy sleep', a phrase coined by Dr Nerina Ramlakhan, a sleep coach at London's Capio Nightingale hospital, and author of the book Tired But Wired.

'It's not a scientific term, but clients say that's what their head feels like,' she explains. 'They are asleep but it's not restful. It's a jangly, information-filled sleep where the brain is still highly active.'

Lisa Myers, 34, CEO of an internet search company, knows this feeling only too well. She used to suffer appalling semi-somnia until she realised how much her work was suffering.

'Most mornings, I'd wake-up completely wired, as if I'd already drunk too much coffee,' she says. 'My head felt swollen from all the issues I had to deal with. I need eight hours sleep at night to function but sometimes I got as little as four. It left me not just tired, but agitated and unable to focus.'

So why has semi-somnia started plaguing us now? 'We've spent five years researching this with 30,000 sufferers and technology is probably the main cause,' says Jean Gomes, chairman of  The Energy Project - a consultancy dedicated to helping people counteract tiredness issues.

'Humans have always had stress and that does interfere with sleep, but work and home used to be separated by time and space: leaving the office meant you had to switch off.

'You may have had a stressful day, but your mind could process problems overnight and you'd wake the next day refreshed. Now the ways we relax - shopping online, tweeting while watching television and checking Facebook- mean our brains are in a permanent state of arousal.' When bedtime comes around, this can cause big problems.

For us to sleep, three main things happen: the decline in light triggers the production of the sleep-inducing hormone melatonin, our temperature starts to fall and our mind and body relax, allowing our nervous system to switch off. Using technology interferes with each of those steps.

Studies have found bright screens can reduce melatonin levels by almost a quarter, while research has shown that people exposed to the radiation given out by mobile phones before bed take longer to enter the deepest stages of sleep - and spend less time there.

Then there's the fact that what you read online could keep your mind whirring. 'If I check my company's Twitter or Facebook accounts before bed or in the middle of the night, there's always something to respond to,' says Jemma, who lives in Scunthorpe. 'Dealing with it is the only way to get back to sleep - otherwise I'll just worry about it.'

Sleep is when the mind processes the information we've taken in throughout the day, but the huge amount of material we now consume online can simply be too much to deal with.

'The part of the brain that deals with information processing is relatively small - and it can't cope with the sheer amount of input it's getting now,' says Dr Ramlakhan.

The result is, we're spending longer in the part of sleep where we process information and less time in the deep restorative sleep we need to refresh us. Then we're waking up exhausted. Yet most of us don't realise this is what's happening unless we stop.

Marketing executive Engi Bally, 30, of Windsor, Berks, certainly didn't until she moved to a job with a strict 'no contact outside working hours' policy: workers were explicitly banned from looking at emails or work projects outside office hours. She found her energy levels changed dramatically.

'Now I drink a cup of coffee in the morning for pleasure - not four just to get me started,' she explains.'

My old company expected me to be available 24/7. I would sleep with my phone and laptop in the bed, so I could deal with things immediately.

'It would probably only happen twice a night - I'd be awake for an hour in total - and I didn't really think it was a problem. It was only once I stopped that I realised how tired it was making me.'

Thankfully, as Engi proves, it is possible to recapture your sleep, but the big question is how? First, be aware that a perfect eight hours sleep doesn't begin when you climb into bed - it's a day-long process.

Experts believe the reason our mind goes into information overload is not just the sheer amount of material we're taking in, but that we've stopped taking any downtime. Once, if a friend was late to meet you in a cafe, you would spend the time gazing idly around the room, allowing your mind to wander.

That allowed your brain to process some of the information it had absorbed, reducing its late-night workload. Nowadays, it's more likely that you'll check your phone or look online, causing yet another influx of information for your mind to handle.

'Take information "minibreaks" every 90 minutes through the day to give your mind some space,' says Dr Ramlakhan. 'Drink lots of water. Your bladder will then force you to take a time out - and don't take your phone to the bathroom with you.'

Other good times to take an 'input break' are while on public transport and in queues. If you do use gadgets in the evening, set the screen brightness to low and confine sessions to less than an hour - short sessions have not been shown to affect significantly melatonin suppression. Enlarge the type size and keep the device as far from you as possible to decrease your light exposure.

When it comes to emails, don't check work ones or those from people who might leave you worried or anxious if at all possible. 'I found this really hard at first,' says Engi.

'You start to believe that disaster will occur if you don't reply immediately - it's also hard for your ego to realise you aren't needed 24-7.It took me two weeks to get used to switching off, but I didn't realise how much it affected me until I did.'

If your issue is not so much falling or staying asleep, but feeling rested afterwards, Dr Ramlakhan says it's important to have an evening ban on Twitter or any other site where the content is updating at high speed.

'I'm not aware of any published science around this yet, but in my practice people tell me the greater the speed of information they read before bed, the more 'fizzy' their sleep is.'

But the biggest tip of all is that an hour before bed you must turn all gadgets off. Experts call this the 'electronic sundown', which allows your natural sleep systems to switch on.

'Clients know I have a 9pm cut-off and, unless it's an emergency, I won't deal with emails until the next morning,' says Lisa Myers. 'Doing this means I work better the next day.'

It's the type of development Jean Gomes is very happy to see.

He says: 'Feeling well and full of energy is a triumvirate of nutrition, exercise and sleep.

'For years now we've been focusing on the first two and letting poor sleep become the new norm. But finally, the tide is turning.'


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