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What’s causing your tiredness?

29 Jun 2020

It’s not always easy to tell the difference between feeling naturally tired and the type of exhaustion that might have a medical cause. Our guide will help

Quick facts:

  • Tiredness is a natural process; a sign you need rest
  • However, if you have felt constantly tired for more than 4 weeks, talk to your doctor as there may be a medical reason

It's perfectly normal to feel tired. Maybe you’ve had a late night, are sleep-deprived because of family demands, or have been working long hours. The tiredness you feel is a signal that you need to stop, slow down and rest. If you’re overweight, pregnant or on certain medications, you’re also more likely to feel tired.

Natural tiredness passes. You go to bed, you sleep and you wake up feeling refreshed. But if you’ve been feeling constantly tired for more than 4 weeks and no amount of rest or sleep helps, there might be a medical reason.

Here we outline some common conditions that may be causing your exhaustion.

1. Iron deficiency anaemia

If you feel tired and lacking in energy, you might be anaemic.

Iron deficiency anaemia is caused by a lack of iron. You need iron to make haemoglobin, a protein in red blood cells that transports oxygen around the body. Typical symptoms include tiredness, shortness of breath, heart palpitations and pale skin.

Less common symptoms include headaches, dizziness, tinnitus, hair loss, painful ulcers in the corners of your mouth, spoon shaped nails and restless legs.

Anaemia may be caused by a diet that’s low in iron, conditions such as stomach ulcers or Crohn’s disease, surgery, or in women it could be due to heavy menstrual bleeding, pregnancy or childbirth.

For vegetarians who eliminate meat, anaemia can be due to an iron deficiency. For vegans, who give up all animal products including dairy, eggs, and even honey, anemia can also be caused by vitamin B12 deficiency.

How your GP can help

Speak to your GP. A blood test will confirm whether you’re anaemic. If your red blood cells are small then you'll be advised to either amend your diet, take over-the-counter supplements or be prescribed iron tablets.

What can you do

Eat more foods rich in iron, such as dark-green, leafy vegetables, pulses such as beans and lentils, pumpkin seeds, wholegrains, fish and lean red meat. If you’re vegan or vegetarian, you might need iron supplements.

2. Nutritional deficiency

Being tired all the time may be a sign of a nutrient deficiency. Here are some of the most common ones that can cause tiredness.

  • Vitamin B12 : Essential for the production of red blood cells, a deficiency can lead to vitamin B12 deficiency anaemia – called pernicious anaemia. This is most often caused by an auto-immune disorder that prevents the body absorbing vitamin B12 from the food you eat. But occasionally it may be caused just by a diet that is low in vitamin B12. Foods that contain vitamin B12 include meat, salmon, cod, dairy products and eggs – so those who are vegan or vegetarian, may also need supplements.
    Symptoms include extreme fatigue, disturbed vision, pins and needles, muscle weakness, irritability, depression, poor memory and concentration.
    A blood test will confirm whether you are low in vitamin B12.
    Treatment is usually with injections or tablets of vitamin B12.

  • Vitamin D3 : Studies have shown a strong connection between vitamin D3 deficiency and fatigue. This is especially common in elderly people who don’t get outside as much. Sunlight on your skin is the best source of vitamin D. Foods that contain vitamin D3 include oily fish, mushrooms, egg yolks and fortified foods.

How your GP can help

Tell your GP about your symptoms. They may need to organise blood tests to identify the vitamins and minerals you might be low in.

3. Hypothyroidism (underactive thyroid)

If you constantly feel exhausted and also have other symptoms such as weight gain, depression, muscle aches, joint pain, dry skin, brittle nails, thinning hair, loss of libido and irregular or heavy periods (in women), you might have an underactive thyroid. This is when your thyroid is not producing enough thyroid hormones, which causes your whole system to slow down — and makes you tired all the time.

How your GP can help

Tell your GP about your symptoms. They may need to organise a thyroid function test. This looks at levels of thyroid stimulating hormone (TSH) and thyroxine (T4) in the blood. A high level of TSH and a low level of T4 could mean you have an underactive thyroid.

An underactive thyroid is usually treated by taking daily thyroid hormone replacement tablets. Certain foods can help to support your thyroid function, including leafy greens, vegetables, fruit, organic lean meat and fish.

4. Depression

Overwhelming fatigue might be a symptom of depression. A recent study shows that fatigue is one of the most frequently reported physical symptoms of depression, occurring in more than 90% of patients.

Psychological symptoms of depression might include continuous low mood or sadness, poor concentration, low self-esteem, feeling tearful, irritable, anxious and worried.

Other symptoms might include moving and speaking more slowly, changes in appetite, unexplained aches and pains and lack of energy.

How your GP can help

If you experience symptoms of depression for most of the day, every day for more than 2 weeks then you should talk to your doctor. When you’re depressed it may seem that nothing makes a difference, but it’s vital that you seek help.

Treatment may involve making lifestyle changes such as eating healthily, exercise, giving up smoking or drinking (nicotine and alcohol can make depression worse).

Your GP may refer you for talking therapies such as Cognitive Behavioural Therapy (CBT) or prescribe medication to help you recover. It’s important that you do get help. Left untreated, depression can interfere with all aspects of your life.

5. Other causes your GP might investigate

This is by no means an exhaustive list of all the many medical causes of tiredness.

Your doctor will ask you questions about the symptoms accompanying your tiredness and may carry out tests.

These include inflammatory conditions such as coeliac disease, in which your immune system reacts to a protein in gluten.

Other considerations include sleep disorders such as sleep apnoea, in which you wake on numerous occasions during the night because your breathing stops and starts. This symptom is often related to obesity, so if you suffer from that and/or experience a lot of daytime sleepiness, ask your doctor about sleep apnoea.

Your tiredness could also be down to mental fatigue. It's worth discussing this with your doctor, as a psychological option such as a course of talking therapy might help you to recover.

In some cases, unexplained tiredness might be a symptom of something more serious. That’s why it’s better to talk to your doctor about it, rather than ignore the issue. It’s what we’re here for.

Reviewed by: Dr Harriet Bradley, Livi Medical Director

Last updated:
29 Jun 2020