ESTIMATES vary but it's thought that up to 10% of patients visit their doctors because of fatigue.
But, while it is true that fatigue can be a symptom of a serious health problem, in most cases it is about our lifestyle and what we are/are not doing.
Here are some of the most common causes of fatigue and some easy steps to overcome them.
You probably need eight hours of quality sleep a night although international sleep expert Rubin Naiman says he enjoys nine. So don't feel guilty if sometimes you need a little more.
And remember that it's sleep before midnight rather than after that is the most valuable. In fact sleep researchers suggest every hour before 12am may be worth two hours, while every one after that time is worth half an hour.
If you're a poor sleeper, try listening to relaxing music before bedtime, making sure you have heavy curtains so your bedroom is dark.
Wear ear- plugs if you live near a noisy road or with someone who snores and write down everything down that you're concerned about before you go to bed and put the list out of reach until tomorrow.
Natural linen and a soothing decor can also help improve sleep quality, says Naiman.
Lack of nutrients
Australian health research suggests about 20 to 40% of women of child-bearing age fall short of getting the recommended amount of iron from their diet.
If you are female, a vegetarian, vegan or pescatarian and you think fatigue may be linked to heavy menstruation or your diet, you can get a blood test that will gauge your iron levels.
If they are low, your doctor may recommend a supplement.
Extreme dieting can really wear you out. To maintain energy, you need to eat regularly - three to four times a day and drink plenty of filtered water to avoid dehydration, says nutritionist Zoe Bingley-Pullin, author of Eat Taste Nourish.
When sugar-attacks hit about 3-4pm don't eat empty sugar kilojoules.
Low-fat cheese and wholewheat crackers are a great snack because the protein and complex carbohy- drates will keep you satisfied. You could also try some low-fat yoghurt.
Stress can wring you out like an old dishrag. To reduce energy-sapping stress you may need to alter some of the conditions under which you work, for example, reduce overtime, delegate, make sure you take regular breaks or even renegotiate your position within your workplace. No matter whether you are able to make any, or all of these changes, what you absolutely must not do if you want to reduce stress and fatigue is bring work home, or answer your mobile phone to work calls after hours, says Andrew May, author of Flip the Switch
Too little exercise
Even the thought of getting off the couch may seem exhausting.
But the irony is that it's lack of exercise that can slowly make you more sluggish.
Engaging in moderate physical activity for a half hour or longer most days of the week may decrease stress, improve mood and leave your feeling energised, say researchers at the prestigious Mayo Clinic in the United States.
Aim for 30 to 40 minutes of exercise a day and include something that gets your heart rate up as well as some stretching and some resistance exercise.
When to call the doctor
If fatigue lasts longer than two weeks or is accompanied by other symptoms such as fever, weight loss, nausea, hoarseness or muscle aches. Fatigue can be related to diabetes, depression, thyroid or adrenal gland imbalance and to heart, liver or kidney disease.