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Tiredness and Fatigue

With the demands of work, home, children, friends and social life, it's no wonder so many people feel tired out every now and then these days. Indeed, it seems as if fatigue is becoming an all-too-normal part of 21st-century life. According to the Royal College of Psychiatrists, most people feel tired from time to time, but one in every five people feel unusually tired and one in 10 has prolonged fatigue.

According to the NHS, everyone experiences tiredness at times. But fatigue is when the tiredness is often overwhelming, and you don’t feel better after sleeping and resting (i).

The National Institute of Health and Care Excellence (NICE) also points out that one study show 1.5 per cent of people see their GP with a new symptom of tiredness or fatigue every year, while other studies show consistently that five to seven per cent of people seeing their doctor or another healthcare practitioner complain of fatigue (ii).

Everyday causes

There are lots of reasons why you may feel exhausted, from being under too much stress to not getting enough exercise or sleep.

Other things that may leave you feeling wiped out include looking after young children, moving home, getting married, bereavement or the break-up of a relationship, not to mention certain health conditions and prescription medications.

Even your weight could contribute to your low energy levels: if you're overweight your body has to work harder to do everyday things, while being underweight could mean your muscles may not be strong enough to do the same everyday things without becoming tired.

Most importantly, if you’re worried about feeling tired all the time, see your GP to rule out any underlying medical causes.  If you experience persistent fatigue that doesn’t improve – even when you get lots of sleep or rest – you may have a condition called chronic fatigue syndrome (CFS).

Common health causes of tiredness

If you’re persistently tired, it could be caused by an underlying health issue, such as one of the following:

Low blood sugar

Hypoglycaemia – or low blood sugar – is when your levels dip too low (unlike diabetes, when they become too high). Hypoglycaemia in non-diabetics is classed either as fasting hypoglycaemia or reactive hypoglycaemia. If your blood sugar level is too low, you may start feeling a bit shaky, woozy and tired. Other symptoms include sudden hunger, headache, shaking, food cravings, sweating, anxiety and fainting.

Eating foods that have a low glycaemic index (GI) may help, as they release sugar slowly into your bloodstream rather than too quickly, which makes your body produce too much insulin. Examples of low-GI foods include oats, pasta, brown basmati rice, pulses and most fruits and vegetables.

Underactive thyroid

Hypothyroidism is when your thyroid gland doesn’t produce enough of a hormone called thyroxine. Since thyroxine is involved in metabolism, not producing enough can cause symptoms including persistent tiredness. Other symptoms include unexplained weight gain, aching muscles and low mood, plus you may feel the cold more than usual.

This condition is more common in women than men (one to two people in every 100 in the UK are thought to be affected by hypothyroidism, with the condition affecting 10 times more women than men (iii) ). Middle-aged women are believed to be most at risk, but many could have hypothyroidism without realising it because the symptoms are often mistaken for general tiredness. Hypothyroidism is diagnosed via a blood test and is easy to treat with a tablet that replaces the thyroxine in your system. You can discover more about thyroid disorders and remedies in our guide.

Coeliac disease

Around one in 100 people in the UK is thought to have coeliac disease (iv), which is caused by a reaction to gluten (a protein found in grains including wheat, barley and rye). Whenever you eat foods that contain gluten, your immune system attacks the gluten and causes damage to your intestines. As a result, your body may not be able to absorb nutrients properly, which can lead to exhaustion and malnutrition. Treatment for coeliac disease involves cutting out gluten from your diet.


Depression can often make people feel drained because it may stop you from sleeping properly or make you lose your appetite. Find out more about the signs and symptoms of depression.

The Mental Health Foundation claims almost 20 per cent of people in the UK aged 16 and older experience symptoms of anxiety or depression, with more women affected than men (22.5 per cent of women compared with 16.8 per cent of men) (v).

Antidepressants are a common treatment for depression, but drug-free treatments are available too, including cognitive behavioural therapy and other talking therapies. Meanwhile, you can help yourself by keeping active and staying as healthy as possible. According to the mental health charity Mind, eating regularly and keeping your blood sugar stable can also make a difference to your mood (vi).


Iron deficiency is the most common cause of anaemia. Not having enough iron means your haemoglobin levels will be low, so your body may not be getting enough oxygen from your lungs, causing tiredness. Other symptoms include breathlessness, heart palpitations, a tingling sensation in your fingers, light-headedness and general weakness.

Younger women are most likely to have iron-deficiency anaemia. But after the menopause, women have the same risk as men (two to five per cent of adult men and postmenopausal women in the developed world have iron-deficiency anaemia, suggest figures from the British Society of Gastroenterology (vii) ).

If a blood test shows your haemoglobin is clinically low, your GP may prescribe a course of iron tablets. Meanwhile, foods rich in iron include blackstrap molasses, brewer’s yeast, pumpkin seeds, liver, green leafy vegetables and egg yolks.

Why sleep is essential for health

Burning the candle at both ends is a sure way to make you feel tired and unable to concentrate. But not getting enough sleep on a regular basis can play havoc with your health.

According to the NHS, after several sleepless nights you’ll start to notice the effects not getting the sleep you need can have on your mental health (viii). You will find it difficult to concentrate and make decisions, for example, and your mood will feel low. As well as making it dangerous to drive, you may also have a higher risk of having an accident at home or at work. And if you keep on getting less sleep than you need, your risk of developing one of the following medical conditions will get higher:

Heart disease

Not getting enough sleep on a long-term basis may affect your heart, making it beat faster and increasing your blood pressure. Sleep deprivation may also boost the levels of certain chemicals that are thought to cause inflammation, which may also put more strain on your heart.


The NHS claims there’s evidence to suggest those who sleep fewer than five hours a night may have a higher risk of developing type 2 diabetes, possibly because of a link between deep sleep and the body’s ability to process glucose (viii).


Many studies suggest that not getting enough sleep can make you gain weight (viii), with sleep deprived people thought to eat more calories than those who are more rested. This may have something to do with hormones that are linked with appetite, particularly leptin (the hormone that makes you feel full) and ghrelin (the hormone that makes you feel hungry).

Depression and anxiety

If you don’t sleep well for just a night or two, you may notice feeling more down than usual. But not getting enough sleep on a regular basis can also lead to more serious mood disorders such as depression and anxiety.


According to the NHS, there’s research to suggest those who don’t get enough quality sleep have lower libidos and less interest in sex (viii).

Read more about sleep and insomnia for tips on how to sleep – and feel – better.

How to get your energy back

Having a healthy lifestyle can help boost your energy levels if you’re feeling tired some or most of the time. Here are a few things you could try:

Eat little but often

If you’re eating three good meals a day but still feeling tired, try having smaller main meals and healthy snacks every three to four hours to help keep your blood sugar levels stable. Try to make sure you always have breakfast, and opt for healthy foods such as porridge instead of sugary cereals.

Try energy boosters

Good energy levels depend on good nutrition, and there are several nutritional supplements that may help if you feel you’re running on empty.

For instance, if you’re one of the many people in the UK thought not to be getting enough magnesium in your diet, your body may not have a sufficient supply of this mineral to make an important molecule called adenosine triphosphate (ATP is where your cells store energy from food).

Immune deficiency can also drain your energy, especially if you suffer from frequent colds or other illnesses. A high-strength multivitamin and mineral supplement may help to support the immune system as well as provide B vitamins, which are required for the conversion of food to energy in the body.

Avoid stimulants

According to the NHS, too much caffeine – found in tea, coffee, colas, energy drinks and chocolate – can disrupt your sleep and make you feel wound-up as well as tired (ix). So try to limit how much caffeine you drink by only drinking caffeinated tea, coffee and soft drinks in the earlier part of the day and switching to decaffeinated drinks after that.

Alcohol can also disrupt sleep if you drink too much during the evening, making you wake up during the middle of the night. Instead, avoid drinking late at night, and stick to the government’s recommended intake (14 units a week spread over three or more days for men and women).

Drink more water

It’s also a good idea to replace some of the caffeinated drinks and alcohol in your diet with water. If you don’t drink enough water, you may start to feel dehydrated, which can make you feel tired.

Be more active

Exercise may be the last thing you feel like doing when you’re tired, but being physically active is widely thought to help increase energy levels. However, if you’re new to exercise, try not to overdo it in the beginning, as working out too often and for too long can drain your energy if you’re not used to it.

Maintain a healthy weight

If you’re overweight or obese, the strain all that extra weight puts on your heart can make you feel exhausted. But getting back down to a healthy weight can give you back your energy. Eating a healthy diet combined with physical activity is the best way to maintain a healthy weight.

Reduce stress

Generalised anxiety disorder (GAD) is common in the UK, affecting an estimated five per cent of the population (x). You may have GAD if you feel worried and anxious most of the time, rather than just now and then when faced with stressful events. One of the symptoms of GAD is tiredness, along with many others including restlessness, irritability, feeling constantly on edge, fast or irregular heartbeats and shortness of breath.

Too much stress at work also drains your energy. But while it’s impossible to avoid stress altogether, making more time to relax can help you cope with it more effectively.

Fish oils may help, especially if you’re one of the many people who don’t eat the recommended two to three portions of oily fish a week. That’s because there’s some evidence they may help you cope more effectively with stress (xi). If you’re a vegetarian or vegan you can still benefit from an omega-3 supplement, thanks to the availability of products that contain the natural triglyceride (TG) form of omega-3, which is sourced from plant organisms called microalgae rather than fish.

Siberian ginseng is also widely used to counteract the negative effects of stress, particularly in Russia and Eastern Europe (xii).

Five energy foods

Eating a healthy, balanced diet that includes some starchy foods, at least five daily portions of fruit and vegetables, some protein and dairy foods may help counteract tiredness and keep your energy levels normal.

If you’re eating three good meals a day but still feeling tired, try having smaller main meals and healthy snacks every three to four hours to help keep your blood sugar levels stable. Try to make sure you always have breakfast, and opt for healthy foods such as porridge instead of sugary cereals.

Meanwhile, try one or more of these energy-boosting foods:


Blood sugar problems are among the main causes of low energy levels, but foods that have a low glycaemic index (GI) can help. That’s because the sugar in low-GI foods breaks down slowly to deliver a steady supply of energy. One of the lowest-GI fruits is cherries – though you could also try apples, pears, grapefruit, oranges, strawberries, blackberries, blueberries or peaches.

Nori seaweed

Anaemia can also cause tiredness, so it’s a good idea to make sure you’re getting enough iron in your diet. As well as boosting your haemoglobin, iron is required for the production of adenosine triphosphate (ATP), which is where your cells store energy after it’s been broken down from food. Red meat is a good source of iron, but nori seaweed is a good alternative. Other iron-rich foods include green leafy veg, sesame seeds, shellfish and eggs.


Because lentils are a balanced mix of protein and carbohydrate, they are a good source of sustained energy. The soluble fibre in lentils also slows down the release of sugars, while an amino acid called tyrosine – found in protein foods – produces brain chemicals that help keep you feeling alert. Lentils also have a low GI. Other legumes that may help to keep you going include beans and chickpeas.

Low-fat dairy

Dairy foods are a good source of protein too. As well as containing tyrosine, protein increases the production of a hormone called glucagon, which helps keep your blood sugar levels steady. Milk, cheese and yoghurt also have a low GI and contain B vitamins, which are thought to play a role in converting food into ATP. Choose dairy foods that are low in fat, such as cottage cheese and skimmed milk.


Nuts are good energy foods, especially almonds, as they contain nutrients such as manganese, copper, magnesium, calcium, riboflavin and biotin – all of which play an important role in the production of ATP. Technically a seed rather than a nut, almonds also contain the antioxidant vitamin E and are a good source of protein. Almonds also have a low GI, along with other nuts such as walnuts, hazelnuts, peanuts and pecan nuts.

Being overly tired or fatigued can be down to a number of things, so this guide should help to discover the underlying cause. For even more advice on a number of common health conditions, discover a range of articles in our health library.


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  13. , , et al. Fish oil and neurovascular reactivity to mental stress in humans. Am J Physiol Regul Integr Comp Physiol. ;304(7):R523-30


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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

Our Author - Christine Morgan


Christine Morgan has been a freelance health and wellbeing journalist for almost 20 years, having written for numerous publications including the Daily Mirror, S Magazine, Top Sante, Healthy, Woman & Home, Zest, Allergy, Healthy Times and Pregnancy & Birth; she has also edited several titles such as Women’ Health, Shine’s Real Health & Beauty and All About Health.

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