Do you regularly struggle with tiredness throughout the day? Feeling tired is very common – it’s estimated that up to 45% of us suffer from fatigue. With so many possible causes, it can be hard to pinpoint why your energy levels might be dipping.
What’s the difference between tiredness and fatigue?
Tiredness is something we all experience, and we can usually recover by sleeping and resting. There’s no one definition of fatigue, but researchers have suggested it has many dimensions, including physical, cognitive, mental, motivational and emotional factors. It’s sometimes defined as a kind of tiredness that doesn’t get better with rest.
So, why am I always tired?
Despite how common it is, fatigue is still poorly understood. There are many natural and obvious key lifestyle causes of tiredness, including:
- Difficulties at work or at home
- Lack of sleep
- Stressful experiences
- Drinking too much alcohol
- Drinking large amounts of caffeine
- Prescription medication like antidepressants or sleeping pills
- Having a baby
Tiredness could be caused by too much screen time, which can make it harder to fall asleep. It can also be caused by a recent sickness, including viral infections like the flu or Covid-19 and bacterial infections like pneumonia or a UTI.
Why do we feel more tired in winter?
It’s natural to experience more tiredness symptoms during the winter. ‘Winter fatigue is linked to shorter days and a more stressful environment for the body, with lower temperatures and more infections,’ explains Dr Guyomar.
‘It’s common to need an extra half an hour or three-quarters of an hour of sleep every night.’
What are the other key causes of tiredness?
Sometimes tiredness and fatigue can be a symptom of an underlying medical condition or illness, including chronic infectious diseases, endocrine diseases (related to hormonal imbalances), autoimmune diseases and sleep-related conditions. These can include:
1. Depression, burnout or other psychological causes
About 1 in 5 patients who go to the doctor because of tiredness suffer from a depressive disorder. According to one study, more than 90% of patients with depression experience fatigue.
Psychological causes are often to blame for persistent fatigue. ‘Fatigue with psychological causes is most noticeable in the morning when you get up and is associated with other symptoms such as sleep disturbances and loss of vitality and motivation,’ says Dr Guyomar.
‘Often, depression is the cause. But it can also be due to anxiety disorders, bipolar disease in the depressive phase or anorexia.’
Persistent tiredness is also one of the major symptoms of burnout – a loss of motivation and emotional depletion caused by work-related stress.
2. Iron deficiency anaemia
Anaemia can also cause feelings of tiredness. ‘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,’ Dr Guyomar explains.
‘When our cells don’t get enough oxygen due to iron deficiency anaemia, we may feel fatigued. This fatigue can be more or less severe depending on the extent of the anaemia. It’s a very common cause of tiredness.’
Anaemia has several potential causes, including diets low in iron, conditions like stomach ulcers or Crohn’s disease or heavy menstrual bleeding, pregnancy or childbirth.
If you constantly feel exhausted and have other symptoms such as weight gain, lack of concentration, muscle aches, thinning hair, irregular periods or loss of libido, you might have an underactive thyroid – or hypothyroidism.
‘Hypothyroidism is a malfunction of the thyroid gland, which causes a decrease in thyroid hormones, resulting in a slowing down of the functioning of our organs,’ explains Dr Guyomar. This causes your body’s main functions to slow down and makes you feel tired all the time.
A doctor may organise a thyroid function test to check for hypothyroidism. This looks at levels of the thyroid-stimulating hormone (TSH) and thyroxine (T4) in the blood. High levels of TSH and low levels of T4 could signal that you have an underactive thyroid.
4. Sleep apnoea
‘Sleep apnoea is when your breathing pauses during sleep,’ explains Dr Guyomar. ‘These episodes aren’t inherently serious, but they can cause the quality of your sleep to deteriorate, causing tiredness.
‘People with sleep apnoea syndrome may fall asleep during the day and experience headaches as well as have difficulty concentrating,’ she says. ‘Moderate to severe sleep apnoea can also lead to high blood pressure and cardiovascular disease in the long term.’
5. Sleep debt
Sleep debt is the accumulated difference between your optimal number of hours of sleep and the number of hours you actually get. With an estimated 45 million people in Europe having a chronic sleep disorder, many of us will accumulate sleep debt at some point.
Short-term sleep disruption can cause everything from a feeling of tiredness to emotional distress and memory issues, while the long-term implications include hypertension, cardiovascular disease and type 2 diabetes.
If you’ve accumulated sleep debt, try to ease into a more regular sleep routine that will help you catch up gradually.
6. Coeliac disease
Coeliac disease is an autoimmune disease triggered by eating gluten, which affects around 1% of the population worldwide. Fatigue is a common symptom of coeliac disease, but you’ll typically notice other symptoms like bloating, diarrhoea and abdominal pain or discomfort.
7. Chronic fatigue syndrome
If you’ve experienced regular fatigue for 6 months or more, this could be caused by chronic fatigue syndrome, also known as myalgic encephalomyelitis (ME).
‘This often presents alongside joint pain, headaches, sleep issues, concentration and memory disorders, and discomfort after exercise,’ says Dr Guyomar. ‘It only affects between 0.2% and 0.4% of the population, but it’s 3 times more common in women than men. The onset is usually sudden, often following a viral infection.
‘One of the difficulties for patients with chronic fatigue syndrome is that the lack of a clear medical cause means that it can be tough for others to properly understand. The symptoms can cause severe disability and distress.’
‘It’s common to feel tired after a viral illness like Covid-19,’ says Dr Guyomar. ‘This is sometimes known as post-viral fatigue syndrome and can last from 1 week to 4 months.
‘If the fatigue persists for more than a few months, a doctor can investigate further to rule out other causes, including long Covid.’
Should I take vitamins for tiredness?
‘Vitamins and minerals such as magnesium and amino acids are useful when you’ve been diagnosed with a deficiency via a blood test,’ says Dr Guyomar. ‘But they should only ever be used for a short period.’
Always speak to a doctor before taking any supplements for tiredness.
How can I stop feeling so tired?
If you’re looking for ways to boost your energy levels, try these doctor-recommended tips:
- Prioritise your sleep quantity and quality – avoid alcohol and stimulants like tobacco and caffeine in the evening, and create a relaxing routine to help you fall asleep.
- Eat a balanced, healthy diet – and avoid skipping meals.
- Make time for physical activity – on a regular basis, but avoid anything too intense.
- Aim for daily moments of relaxation – you could try yoga, relaxation therapy or meditation.
- Take a short nap – try 20 minutes after a meal.
When should I speak to a doctor about my tiredness?
Speak to a doctor if your tiredness or fatigue:
- Persists even with good sleep and rest
- Prevents you from carrying out your daily activities or affects your mental health
- Lasts for more than 6 months
- Is accompanied by other symptoms such as fever, abnormal weight loss or gain, pain, abnormal thirst or loss of appetite.
This article has been medically approved by Dr Céline Guyomar, a medical doctor at Livi