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Top unexpected causes for feeling tired

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If you've been feeling constantly tired or lethargic, the cause could be more than simply a lack of enough sleep. For those getting their eight hours a night who still feel exhausted throughout the day, it could come down to something as simple as leaving your phone by the bed, or the time you choose to exercise.

Nutritionist Dr Marilyn Glenville shares her top causes of tiredness, and her solutions for boosting energy levels...

Scroll below for full list


The layout of your bedroom can affect how you sleep at night

Leaving your phone by your bed

Sleeplessness, headaches, fatigue and dizziness can all be symptoms of electrical sensitivity, which interferes with your body's natural rhythms, so avoid leaving phones and digital clocks by the side of the bed as these can actually disrupt your sleep.

The time of day you choose to work out

You should not exercise intensely before bed, as this makes your adrenaline and heart pump which will make sleeping difficult. Also if your exercise routine is too intense, long or vigorous for your current level of fitness instead of energising it will be draining you. Instead do exercises such as running or aerobics in the morning, and focus on milder activities in the evening such as a walk or a yoga session.

Avoid leaving phones and computers by your bedside at night

The layout of your bedroom

Almost 40 per cent of the population suffers from some form of insomnia – and a disrupted night's sleep affects you physically and mentally. Make sure you have a comfortable mattress and that your bedroom is a calm and relaxing place – a well ventilated but not cold room is ideal as our body temperature falls at night to help us fall asleep.

You're not drinking enough water

You can usually reverse mild to moderate dehydration by increasing your intake of fluids, but severe cases need immediate medical treatment. Aim for 6 to eight glasses of water or herb teas a day and don’t wait until you get thirsty to drink. Reduce your alcohol, tea and coffee intake as these are dehydrating.

What you're having for lunch

A food intolerance can cause lethargy and irritability, plus it triggers a response from the immunity system which uses up a huge amount of energy. The most common food culprits are wheat, dairy and sugar. If you suspect that you have a food intolerance keep a food diary for a few weeks and see if there is a connection between your tiredness and a specific food. Try eliminating that food and see if it makes a difference.

Dehydration can also be a cause of fatigue

Low sugar levels

Tiredness, extreme thirst and increased urination could be a sign of undiagnosed diabetes. If you're concerned, visit your GP who can run a blood test. Low blood sugar levels also cause tiredness – so make sure to avoid sugar and refined processed foods as well as juices, cigarettes and caffeine and eat every three hours, choosing foods such as seafood, eggs, hummus, green vegetables and fruits such as pears, grapes and apples.

Your iron levels are low

Anaemia is caused by a lack of iron and symptoms include tiredness, dizziness as well as a racing heart. If you think this could be the cause of your exhaustion, visit your doctor. To reduce the risk of anaemia, make sure to eat a balanced diet which includes plenty of green vegetables.

Dr Marilyn Glenville is the author of The Natural Health Handbook for Women. For more information head to

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