Slideshow: 12 causes of fatigue and how to fight it

Not enough sleep

Don't overlook the obvious – one of the most common causes of fatigue is getting too little sleep. The NHS cites one UK study in which 36 per cent of people reported having insomnia. If you’re fond of burning the midnight oil, lack of sleep may be causing your fatigue.

Solution: Sleep for seven to eight hours every night.

Sleep apnoea

Some people think they're sleeping enough, but this sneaky condition gets in the way. Sleep apnoea briefly stops your breathing many times during the night. Each interruption wakes you up for a moment, although you may not be aware of it. The result: you're sleep-deprived despite spending eight hours in bed.

Solution: Lose weight if you’re overweight, stop smoking, and sleep with a CPAP (continuous positive airway pressure) device to help keep airway passages open at night.

Not enough fuel

Eating too little is another obvious cause of fatigue, but eating the wrong foods can also be a problem. If you start your day with doughnuts, your blood sugar will peak and crash, leaving you sluggish.

Solution: Always eat a good breakfast. Try to include protein and complex carbohydrates, such as eggs and wholemeal toast. This combination creates sustained energy.

Anaemia

Anaemia is a leading cause of fatigue in women. It occurs when the body doesn’t have enough red blood cells (shown here) to carry enough oxygen to your tissues and organs. Anaemia is easily diagnosed with a blood test.

Solution: Treatment for anaemia depends on the cause. Common iron deficiency can be corrected by taking iron supplements and eating iron-rich foods, such as lean meat, liver, shellfish, beans, and iron-fortified cereals.

Depression

You may think of depression as an emotional disorder, but it causes many physical symptoms as well. Fatigue, headaches and loss of appetite are among the most common symptoms. If you feel tired and 'down' for more than a couple of weeks, see your GP.

Solution: Depression responds well to psychotherapy and/or medication.

Hypothyroidism

The thyroid is a small gland at the base of your neck. It controls your metabolism, the speed at which your body converts fuel into energy. When the gland is underactive and the metabolism functions too slowly, you may feel sluggish and put on weight.

Solution: If a blood test confirms your thyroid hormones are low, synthetic hormones can bring your thyroid levels back up to normal.

Caffeine overload

While many of us consider coffee a defence against fatigue, it can be a Trojan horse. Caffeine is a stimulant and improves alertness and concentration in moderate doses, but research indicates too much caffeine actually causes fatigue in some people.

Solution: Consume caffeine in moderation. Caffeine is found in coffee, tea, chocolate, soft drinks and any medications that contain caffeine.

Hidden UTI

If you've ever had a urinary tract infection (UTI), you're probably familiar with the burning pain and sense of urgency, but the infection does not always announce itself with such obvious symptoms. In some cases, fatigue may be the only sign. A urine test can quickly confirm a UTI.

Solution: See your GP. Antibiotics are the cure for UTI's, and the fatigue will usually vanish within a week.

Diabetes

In people with diabetes, sugar remains in the bloodstream instead of entering the body's cells, where it would be converted into energy. The result is a body that runs out of steam despite having enough to eat. If you have persistent, unexplained fatigue, ask your GP about being tested for diabetes.

Solution: Treatments for diabetes may include lifestyle changes, insulin therapy, and medication to help the body process sugar.

Heart disease

When fatigue strikes during everyday activities, such as cleaning the house or weeding the garden, it can be a sign that your heart is no longer up to the job. If you notice it’s becoming increasingly difficult to finish tasks that were once easy, talk to your doctor about heart disease.

Solution: Lifestyle changes, medication, and therapeutic procedures can get heart disease under control and restore your energy.

Food intolerance

Food intolerance can make you sleepy. If your fatigue intensifies after eating certain foods, you could have a mild intolerance to something you're eating.

Solution: Try eliminating foods one at a time to see if your fatigue improves. You can also ask your GP about a supervised elimination diet.

Chronic fatigue syndrome (CFS)

If your fatigue lasts more than six months and is so severe that you can't manage your daily activities, chronic fatigue syndrome is a possibility. CFS can have various symptoms, but the main one is persistent, unexplained exhaustion.

Solution: While there's no quick cure for CFS, patients often benefit from changing their daily routine, learning better sleep habits, and starting a gentle exercise programme.

Fast solution to mild fatigue

If you have mild fatigue that isn't linked to any medical condition, the solution may be exercise. Research suggests healthy but tired adults can get a significant energy boost from a modest workout programme. In one study, participants rode a stationary bike for 20 minutes at a mild pace. Doing this just three times a week was enough to fight fatigue.

More reading on fighting fatigue

• Sleep and restless leg syndrome
• What is sleep apnoea?
• Diet for depression
• Heart disease and exercise
• Living with shellfish allergy
• Chronic fatigue syndrome
• Hypoglycemia and diabetes