If you're anything like the rest of us, your response when someone asks how you are is likely to involve the phrases "totally knackered", "slept badly", "I'm shattered" and "need coffee now". We're tired, and it's affecting our quality of life. "For so many of my patients, having energy is a distant memory," says Dr Ginni Mansberg, GP and the co-author of Why Am I So Tired? ($47.95, Deep Books). "They feel like they're muddling their way through life, feeling forgetful and unfocused with no battery life left - that's not normal." There are sound reasons for experiencing this modern plague, but a study in the British Journal of General Practice found that, of 325 patients with fatigue, only eight per cent had an actual medical reason for it. "It's frustrating for patients, as doctors don't really handle consultations for tiredness very well," Dr Mansberg says. "It doesn't fit into the tidy framework of 'disease' that we learnt about."

Research also shows women are more likely to say "I'm tired" than men. A study presented at the 2006 World Organization of Family Doctors conference found a quarter of all people sitting in their GP's waiting room felt exhausted, and that 62 per cent of these bleary-eyed patients were women. And lack of sleep doesn't cover it all. A UK survey of 2000 women, whose average age was 35, found most reported feeling tired all the time, and that the exhaustion was caused by the competing demands of home and work, as well as poor eating habits. "Often people don't have the road map to deal with tiredness so their doctor is the first port of call. But there's a lot you can do to get your zing back before you go to your GP," says Dr Mansberg. So we grilled her for the best DIY tiredness fixers. Because really, we don't want to be yawning in people's faces anymore.

Your sheep count is too high

That persistent car alarm. Your partner's snoring habit. Your Stress-Head-of-the-Month Club membership. There's a lot to keep you up, so is it any wonder that two-thirds of women have trouble sleeping at least two nights a week? Roughly speaking, you need around eight hours of sleep a night to function. But that number is a rough guide, not the gospel. "Think of sleep as a bank account - you need to withdraw between seven and eight hours' worth a night to cover you," says Dr Mansberg. "Making a couple of excess withdrawals here and there is fine - it's not what you do on one night that makes you tired, but a pattern over time." Constantly running in overdraft will make you cranky and forgetful, and put you at risk of health problems (think extra kilos, depression and heart problems). A recent US study found that women who had trouble falling asleep more than twice a week or who took longer than 30 minutes to drift off had a higher risk of heart disease than men who had sleep troubles.

DIY fix The first mistake made by many of Dr Mansberg's tired patients is that sleep is low on their list of priorities. "It's scheduled in only after the washing is done, the bills are paid and that TV show is watched," says Dr Mansberg. "If you are sleep deprived, grab your BlackBerry and schedule in eight hours every night, and then say, 'I don't have time to do the washing tonight, I need to sleep'." Once you've scheduled in eight hours, Dr Mansberg suggests working on your "sleep hygiene" (a term to describe basically everything involved in the process of getting to bed). Try her tweaks for dropping off:

1. Have a low-GI snack, like yoghurt or dried apricots, an hour before bed - hunger can stymie sleep.
   Eating a large, late or spicy meal can make you feel restless. Try smaller, earlier, less fiery dinners.
   That midnight trip to the loo can kill your snooze, so drink lots during the daytime, then cut back on fluids from 6pm.
   Cut back on alcohol and don't drink coffee after 4pm. Both mess with sleep.
   Say goodnight to laptops, TVs and iPhones an hour before bedtime.
   Insomniacs need to get into a good bedtime routine by going to bed and getting up at roughly the same time every day (even on weekends). This can retrain your brain to sleep at night.

Taking too many trips down What-if Avenue

While short-term stress can jolt you to life, prolonged periods of pressure literally drain your body's battery. Anxiety triggers stress hormones that shoot their way through your bloodstream, your muscles clench up ready for action and your heartbeat accelerates to prep you for physical exertion. All good if you're about to run a marathon, but if your body is continuously in fight-or-flight mode, the effects will wear you out. "Stress is a curious thing; the effects on your body are not consistent. And the effects you feel are rarely in proportion to the stressor that's at fault. The variable is you," says Dr Mansberg. Which is why your best mate gets off on packing her weekends tighter than Brüno's bum cheeks but you have a conniption if you don't get to spend Sunday afternoons in bed.

DIY fix Balance your perspective. "People tend to catastrophise when they feel stressed," says Dr Karen Reivich, research associate at the University of Pennsylvania's Positive Psychology Center and co-author of The Resilience Factor (amazon.com). Next time a problem has you lying in bed thinking what-ifs, try Reivich's fix: draw a line down the middle of a sheet of paper. On one side, list all your worst-case scenarios until you come up dry ("...and then the virus will spread to my brain and kill me"). On the other side, write down the best possible outcome for the situation ("...my brain surgeon turns out to be McDreamy, who falls madly in love with me"). Balancing catastrophic scenarios against their best-case counterparts makes it clear that neither is likely to happen, so you can rest assured that the outcome will probably be somewhere in the middle and something you can handle. Or, during the day: "Grab a different perspective, from a friend, or a counsellor. Psychologists are trained to help people deal with their issues, so ask your GP or a friend for a recommendation," suggests Dr Mansberg.

Your diet is more offbeat than Rodney Hide's dancing

Forgetting to put on mascara before you leave for work: fine. Forgetting to eat: not fine. "I cannot believe the number of tired women I see whose breakfast is a coffee, or three," says Dr Mansberg. "To kick-start your day and feel awake, you absolutely have to fill your tank with fuel." Coffee is packed with antioxidants, but you also need to have a low-GI brekkie such as Weet-Bix or porridge to sustain your energy levels throughout the morning. You should also pay attention to your H2O habits - a recent report from the National Health and Medical Research Council in Australia stated that losing as little as two per cent of your total body's fluid through dehydration can make you feel off, physically and mentally. There's also evidence that low iron levels in women can affect mental fatigue, so get your iron status checked - ask your GP for a blood test.

DIY fix "Diets are so yesterday in the medical and nutritional world - they should be banished from yours," says Dr Mansberg. No prizes for guessing what the doctor's anti-tiredness eating orders are: down more vegetables, fruit, lean meat, dairy and wholegrains, and scoff less processed foods. And Dr Mansberg says that old 2L of water a day figure is still a fairly good guide: "But of that 2L, around 700ml will come from your food. Of the remaining 1300ml, not all of that has to be water. Tea, coffee and low-fat milk all count. As for those hot brews, packed with antioxidants, they're actually a pretty good alternative," says Dr Mansberg.

Your runners are growing cobwebs

If you're too tired to lace up your runners, you can't afford not to. "Studies show a very strong link between lack of physical activity and fatigue, especially among women," says Dr Mansberg. "You cannot feel full of beans if you don't break out in a sweat with 30 minutes of aerobic exercise on most days of the week." A 2008 study by the University of Georgia in the US found that sedentary people who regularly feel fatigued can up their energy levels by 20 per cent and decrease their fatigue by 65 per cent by doing regular, low-intensity exercise. Think you're too beat to work out? Consider this: exercise has even been shown to boost energy levels among people with medical conditions associated with fatigue, such as cancer and heart disease.

DIY fix Simple: get back on the workout train. Make a plan to ensure the switch from Sunday sloth-fest to Sunday pilates sticks. Think about tomorrow's workout today. An athlete's mindset starts with vision and ends with determination. No, we didn't read that in a fortune cookie; it's just how it works. Write down when you're going to exercise (what time), what you'll do (treadmill, sit-ups during the ad breaks of Shorty) and your goals (feel more alert and less dough-like). Time of day counts, too. "Late workouts will make you sleepier come bedtime, but you have to time them right," says James Maas, a social psychologist at Cornell University, US. "The best time is between 5 and 7pm. Any later and your adrenalin will still be rushing at bedtime."

Got that? Now all that's left for you to do is pull on those comfy jammies and tuck yourself in. A good night's sleep is coming your way. Sweet dreams.