Tiredness, or fatigue, means having less energy than usual. You feel exhausted, either mentally, physically, or both. Tiredness is a normal part of life but if it persists, it may suggest a medical problem.
We have all experienced tiredness (fatigue) at some point. Usually there's a good reason for it ... A new baby keeping you up at night, having a bit of a cold, a late night out on the town, or (less enjoyably) long hours at work. Tiredness that drags on for no apparent reason, however, can be a real problem, and it's incredibly common. One UK survey of over 15,000 people found that 10-18% of those who replied reported tiredness that lasted for one month or longer, and a study looking at GP databases found that around 1.5% of the population report new tiredness every year. It's so common that GPs have an acronym for it ... TATT, which means "tired all the time".
What are the causes of tiredness?
Physical causes of tiredness
Tiredness may be due to a wide range of physical illnesses. Examples include:
- A tendency to be lacking in iron (anaemia).
- An underactive thyroid gland (hypothyroidism).
- Heart failure.
- Chest illnesses (including asthma and chronic obstructive pulmonary disease).
- Addison's disease.
- Bowel problems (for example, coeliac disease).
- Carbon monoxide poisoning.
- Having to get up in the night a lot to pass urine, due to problems such as an overactive bladder or an enlarged prostate gland.
- Breathing problems at night interfering with sleep (obstructive sleep apnoea).
- Vitamin D deficiency.
- Glandular fever.
- Chronic fatigue syndrome.
- Pain from other medical conditions keeping you awake at night.
- Side-effects of some medicines (for example, beta-blockers, medicines to lower cholesterol, some painkillers, some antidepressants).
- Going through the menopause.
Most physical causes of tiredness will cause other symptoms. Some causes of tiredness (such as anaemia and hypothyroidism) may not cause any other symptoms apart from tiredness.
Psychological causes of tiredness
Psychological tiredness is much more common than tiredness caused by a physical problem. Both anxiety and depression can make you feel very tired. Eating disorders can make you feel tired, particularly if you are underweight or overweight. Any cause of a sleep problem will also cause tiredness during the day.
Stress is a common cause of tiredness, either because it interferes with sleep, or because of the effect of having a worry on your mind all the time.
Other possible causes include:
- Domestic violence.
Lifestyle causes of tiredness
Tiredness can be caused by lifestyle. We often try to cram too much into our lives and as they become more and more busy we can get tired. Lifestyle causes of tiredness include:
- Drinking too much alcohol.
- Having an unhealthy, unbalanced diet, including eating too many ultra-processed foods.
- Taking recreational drugs.
- Excessive exercise or total lack of exercise.
- Working night shifts, which may lead to a poor sleep pattern and result in tiredness.
- Big life events such as getting married or moving house.
In many cases no specific cause for tiredness is found.
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What tests are there for tiredness?
If your tiredness is persisting, or if you are unwell in any other way, or if it is having an effect on your life, see your GP. In order to try to find the cause, your doctor will need to ask you some questions. They may need to examine you and they may arrange some blood tests.
Questions you may be asked
These are to help give some clues about the cause of the tiredness, and may include:
- Do you have any other symptoms?
- Sleep: Do you sleep well? Is your sleep interrupted? Do you snore? Has your partner noticed any changes to your breathing at night?
- Mood: Do you feel low, or more worried than usual? Are you under any stress? You may be asked to complete a specific questionnaire about your mood.
- Has your weight changed?
- Do you have heavy periods? (If you are a woman and of menstruating age.)
- How much alcohol do you drink?
- Are you on any medication?
- Can you remember when this started? Did it start suddenly and can you date it from a particular date, event, holiday or illness? Or did it come on more gradually?
- How is the tiredness affecting you in your everyday life?
The doctor may examine you
The doctor may check your weight and height, if it seems relevant. You may not be examined, as it may depend on your answers to some of the questions above; however, the doctor may think it relevant to:
- Check your lymph glands to see if they are enlarged.
- Check your thyroid gland (in your neck) to see if it is enlarged.
- Look at your eyes to see if you might be anaemic.
- Listen to your chest and feel your tummy and the organs in your tummy.
- Check your joints for swelling or inflammation.
- Check the strength of your arms and/or legs.
- Ask you for a sample of your urine to check for sugar (for diabetes) or infection.
Your doctor may feel you should have some blood tests to rule out physical causes for tiredness. In most cases these turn out to be normal. This might include tests to rule out:
- Low iron levels (anaemia).
- Low thyroid hormone levels (hypothyroidism).
- Vitamin deficiencies such as B12 or vitamin D.
- Coeliac disease.
- Any inflammation in your system.
- Any problems with the function of your liver or kidneys.
- Tests for specific infections, such as glandular fever.
Usually no other tests are needed, but if specific medical conditions are suspected, other tests such as a chest X-ray might be necessary.
Do I need to see a doctor?
If you can figure out the reason for feeling tired yourself, and do something about it, then no. If the tiredness is getting in the way of your life, or making you feel unhappy, or you feel unwell, then yes, you should visit your doctor.
You should definitely see a doctor if you feel tired and have lost weight without trying to. Also see a doctor if you have other symptoms as well as being tired, such as coughing up blood, a change in the way your guts are working, heavy periods or a lump somewhere it shouldn't be.
What is the treatment for tiredness?
There is no specific treatment for tiredness. The days of doctors prescribing a "tonic" are over, as there is nothing which really works. The secret is to try to narrow down the cause and then do something about that.
Exercise as a treatment
It may seem bizarre, but physical exercise can actually be remarkably effective for treating tiredness. Any moderate exercise, such as walking, swimming or cycling, can help you feel less tired. Regular exercise is also an excellent way to stay healthy.
Try to improve your sleep
If you're not sleeping well at night, it's tempting to try to "make up for this" by taking naps during the day when you can. This really won't help - in fact, it can put your body clock out of sync, so you may end up sleeping less well at night. There are lots of ways you can try to improve your sleep if you have insomnia and this in turn may improve your tiredness.
Treatments for medical conditions that cause tiredness
If the cause is a medical condition then often treatment of the condition will resolve the tiredness. For example, if you have anaemia then iron supplements can treat this and the tiredness resolves as your blood count improves. It will also be important to look at the cause of the anaemia. For example, if it is due to heavy periods, then using medicines to make the periods lighter will help. If there is a suspicion that the anaemia might be due to a serious condition, such as bowel cancer, then you will need a referral to hospital. If you are found to have an underactive thyroid gland (hypothyroidism) then a pill which replaces the thyroid hormone you are missing is usually very effective and you will find you have more energy.
Treatments for medications that cause tiredness
If the cause is a side-effect of medication, it may be that this can be changed to something which suits you better.
Treatments for tiredness caused by chronic fatigue syndrome (CFS)
If you are found to have chronic fatigue syndrome, you may be referred to a specialist in this illness for help through psychological therapy, graded exercise therapy, or medication.
Treatments for tiredness caused by anxiety or depression
If you have anxiety or depression, this can be helped by talking therapy (counselling), cognitive behavioural therapy (CBT), medication or various other possible treatments.
Treatments for tiredness caused by stress
If you are stressed, it is worth taking the time to sit down and think and talk about it. Is there something which you could change, as this is affecting your health? It may be that you need to re-prioritise things in your life. If work is the stressful problem, could you talk to your manager, change roles, change jobs, cut down your hours? If there isn't anything you can do to change your situation then try to find things which might balance out the stress. People are different, so this would be different for everyone, but may involve a variety of ways to de-stress, such as:
- Regular "me" time.
- Scheduling some fun events.
- Booking a holiday.
- Regular exercise. Ideally something fun rather than something you find a chore. (Ballroom dancing lessons, a weekly walk with a friend, etc.)
Also, avoid bottling up your worries. Try to share them with a friend, or a family member, or consider seeing a counsellor.
There is no single answer for treatment of tiredness. However, even if no cause is found, in most people, it settles on its own with time.
Further reading and references
Tiredness/fatigue in adults; NICE CKS, October 2021 (UK access only)
Why am I tired all the time; NHS 2021