Kevin Courtneyexplains semisomnia.

Sorry, I dozed off there for a minute. What was that word again?

Semisomnia is a state of low-level fatigue caused by a lack of good quality sleep. When someone is properly rested, they function better in their daily lives - but today's high-stress lifestyle means that most people are not getting a proper night's sleep - and not operating at peak capacity during the day.

At least it's not as bad as insomnia. That'll really leave you wiped

While insomnia is classed as a medical condition, semisomnia is not recognised as a proper sleep disorder, yet it affects millions of people, leaving them chronically tired, listless and demotivated. When they're asleep, they're half awake, and when they're awake, they're half asleep. For the average semisomniac, clocking up more than 20 winks each night is but a distant dream.

So how many people suffer from this rare but tiring condition?

A survey, sponsored by the makers of sleepytime drink Horlicks, found that up to 10 million British people could be going around half zonked, mainly due to poor sleeping habits. They're wired up all the time, and thus unable to wind down when it comes to beddy-byes. A Dr Neil Stanley, who probably could do this kind of research in his sleep, set down a list of questions to determine whether someone is a semisomniac. If you regularly wake up exhausted in the morning, find it hard to sleep at night, can't concentrate on normal tasks, can't switch off the stress at the end of the day, or can't stick to a regular sleep routine, then you may fit the criteria of the classic semisomniac.

So, a huge percentage of the adult population are full-time sleepyheads

It's not just affecting grown-ups. Teenagers, hooked up to gadgets and social networking sites, are subsisting on "junk sleep", dozing off in front of a telly or a blinking monitor, and constantly being woken by incoming text messages, e-mails or a new round of their massive multiplayer online game.

I'd like to do something about it, but I'm just too tired to care

Rest easy - Doc Stanley has a few tips for preparing yourself for a proper night's sleep. He recommends switching off all electronic devices, such as TVs, mobile phones and computers. He also suggests clearing your mind of all the to-dos that rattle around inside your head - writing down a list can help ease your troubled mind. You should prepare for sleep in the same way you warm up for exercise - start the process a couple of hours before bedtime - take a relaxing bath, read a book or listen to Classical Chill-Out Vol II. Finally, he suggests you brew up a nice cup of the sponsor's drink, available in all good supermarkets.

Who's got time for all that? I've got to have this article in by the morning

Get a good night's sleep and you'll be clear-headed enough to write a witty, entertaining piece in the morning.

Dream on.

Try at work

"Memo to staff — Denim Day has been changed to Pyjama Day."

Try at home

"Darling, I think checking your e-mails in the bath is kind of defeating the purpose."