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All about fatigue

23 Nov 2022 • 3 min read


We’ve all felt tired at one point or another, but what about fatigue?

What’s the difference between feeling tired and feeling fatigued? In fact, what is fatigue? And what are the symptoms?

When we feel tired, we usually feel a little drowsy or generally sleepy. Our eyes become heavy, our mind a little thick and cloudy, and our concentration a bit of a challenge to maintain (depending on how tired we are).

But when you’re fatigued, it’s about more than feeling like you need to catch up on your sleep, you often have zero motivation and zero energy.1

In a nutshell:

Tiredness – is something that can be relieved by sleep and rest.

Fatigue – is when tiredness feels overwhelming and isn't relieved by sleep and rest.2

What are the symptoms of fatigue?

There are a few tell-tale fatigue symptoms to look out for. They include:3

  1. Chronic tiredness or sleepiness.
  2. Headaches.
  3. Dizziness.
  4. Sore or aching muscles.
  5. Muscle weakness.
  6. Slowed reflexes and responses.
  7. Impaired decision-making and judgement.
  8. Moodiness, such as irritability.
  9. Impaired hand-to-eye coordination.
  10. Appetite loss.
  11. Reduced immune system function.
  12. Blurred vision.
  13. Short-term memory problems.
  14. Poor concentration.
  15. Hallucinations.
  16. Reduced ability to pay attention to current situations.
  17. Poor motivation.

What causes fatigue?

All sorts of things, sometimes in isolation or collectively, can cause fatigue. Generally, the main sources of fatigue can be categorised into three different areas.4

What are the three types of fatigue?

The three types of fatigue are:

  1. Lifestyle-related
  2. Physical health condition-related
  3. Mental health issue-related

Let’s take a look at the three different areas in a little closer detail…

Type 1: Lifestyle

Possible lifestyle contributors include:

  • Physical exertion
  • Lack of physical activity or sleep
  • Being overweight or obese
  • Periods of emotional stress
  • Boredom
  • Grief
  • Taking certain medications
  • Consuming too much caffeine
  • Not having a nutritious diet

Type 2: Physical health

Possible physical health contributors include:

  • Anaemia
  • Arthritis
  • Fibromyalgia
  • Chronic fatigue syndrome
  • Infections – catching a cold or the flu
  • Addison’s disease, a disorder that can affect your hormone levels
  • Hypothyroidism, or underactive thyroid
  • Hyperthyroidism, or overactive thyroid
  • Sleep disorders, such as insomnia
  • Eating disorders, such as anorexia
  • Autoimmune disorders
  • Diabetes
  • Kidney disease
  • Liver disease
  • Chronic Obstructive Pulmonary Disease (COPD)

Type 3: Mental health

Possible mental health contributors include:

  • Anxiety
  • Depression
  • Seasonal Affective Disorder (SAD)

When should I do something about fatigue? 

If you have tried to alleviate the lifestyle factors that may be contributing to your fatigue, e.g. cutting back on your caffeine consumption, making a concerted effort to go to bed earlier, doing some exercise - or less of it, and you still feel fatigued, it’s best you see a GP.5

It’s particularly important you see if a GP if you’re feeling fatigued and find you:

  • Aren’t really sure about what could be causing your fatigue
  • Have a higher-than-normal body temperature
  • Have experienced unexplained weight loss
  • Believe you may have depression
  • Feel extremely sensitive to colder temperatures
  • Frequently struggle to fall or stay asleep

How can I relieve fatigue?

Eat frequently

Eating smaller, regular meals and healthy snacks every three to four hours can help keep your energy levels up.

Eat right

What we put into our bodies can also impact our energy levels, as well as impact how well we sleep.

Eating plenty of non-nutritious food can potentially contribute to fatigue because our bodies aren’t getting the energy it needs to function as it is required to all day long.7 

What’s more, eating the wrong type of food, i.e. processed, high sugar, high fat food, can cause blood sugar spikes.

Fatigue is a common sign of having low blood sugar levels. To avoid this, always try to follow a healthy, balanced diet that contains your five a day and is packed full of fruit and veg, whole grains and protein. For more insight read, ‘What is a balanced diet?’

Lose weight

Being overweight and having to carry that excess weight around with you can be tiring in itself, plus put extra strain on your heart, which can be tiring as well. You can lose weight by – exercising, eating a healthy diet and generally being more active.

Get some sleep

If you’re able to. Having a good night’s sleep, e.g. around eight hours of uninterrupted sleep is the ideal, but due to people’s hectic lives, it isn’t always possible to achieve.

However, there’s no reason why you can’t try to work your way up to this.

For practical advice on acing your bedtime routine and sleeping better read, ’35 tips for a good night’s sleep.’


It’s the key to losing any extra weight and making you feel more energetic (even though it may not necessarily feel that way immediately after a workout!)

Over time, exercise can give you more energy, and it doesn’t have to be anything too major either, it could be something as simple as going for a 15-minute walk.

This article talks you through how to about creating an exercise plan for yourself.

Beat stress

It’s widely acknowledged that the daily stresses and strains of everyday life can get to us all sometimes. This stress can make us want to switch off and sleep too much, which can make us feel more tired, or struggle to sleep well.8 

Either way, stress is a fatigue factor that uses up a lot of our energy, and has the ability to affect us both mentally and physically.

However, there are lots of different tactics you can use to try and reduce your stress levels, which range from going for a jog or a massage, catching up with friends, reading a book, having a long, hot soak in the bath, to walking the dog, listening to music or taking part in yoga or pilates.

For ideas on tackling stress check out, ’10 daily techniques to combat stress.’

Cut the caffeine

According to the Royal College of Psychiatrists, if you feel tired, then you should stop drinking caffeine, which can be found in tea and coffee, energy drinks and some fizzy drinks. Ideally, you should do this by gradually cutting back on it over the period of around three weeks.

If you manage to stay off caffeine for a month and find that you feel less tired, then it may be the caffeine, or one of the main contributors to your fatigue.

Cut back on alcohol too

The NHS recommends that men and women should not regularly drink more than 14 units a week, which is the equivalent to six pints of average strength beer or 10 small glasses of low strength wine.

Ideally, you want to have several alcohol-free days a week, and either cut down or avoid drinking alcohol before you go to sleep. It can potentially interrupt your sleep quality and sap your energy.

For more insight read, ‘3 ways to reduce your alcohol intake.’

Drink more water

You may be good at drinking water throughout the day, but are you drinking enough of it?

According to NHS guidance, we should aim to drink about 1.2 litres (six to eight glasses) of fluids – ideally water - every day to stop us getting dehydrated, which can potentially sap our energy.9

For more on this read, ‘Do you need to drink more water?’

We hope this article has explained all you wanted to know about fatigue and that you now feel a lot clearer on this topic now.

As you’re now most probably aware, fatigue can be caused by one or several lifestyle and physical and mental health factors, and can impact us all in different ways.

This article is purely designed to provide you with an initial overview, if you have any fatigue-related concerns, speak to a medical professional.

How can I get more energy?

Need a boost? We all know the feeling when we’re lacking in energy and get-up-and-go, which can be particularly acute in the winter. In this episode, we’ll look at simple ways to get more energy from:

  • The foods we eat.
  • Exercises and fitness.
  • How we can supplement.

Last updated: 14 June 2022



Author: Donia HilalNutritionist

Joined Holland & Barrett: Jan 2018

Bsc in Nutrition, Registered Associate Nutritionist and Certification in Pre and Post Natal Nutrition

Donia started her career as a freelance nutritionist, later she joined Nestle as their Market Nutritionist to help support their healthier product range, before joining the team at Holland & Barrett in January 2018.

Donia has over 6 years experience as a Nutritionist and also works with clients on a one to one basis to support their goals which include weight loss, prenatal and postnatal nutrition and children’s health.

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