14 Medical Reasons Why You Might Be Tired All The Time


Constantly exhausted? Look out for these telltale signs that something serious is amiss.

Dog-tired all the time and don’t know what to do about it? If you find yourself pressing the snooze button every morning and battling the post-lunch slump every afternoon, you’re not alone. The average Brit spends seven-and-a-half years feeling tired, according to a Healthspan survey.

Frequently feeling tired for long periods of time takes its toll, and can affect your mental health, your physical health and your quality of life. While it’s normal to feel sleepy every now and then, if you’re constantly fighting the urge to drop into a deep slumber, then something could be amiss.

We asked Dr Kat Lederle, head of sleep health at Somnia, nutritional therapist Jo Gray, and personal trainer Luke Gray – co-founders of Feelnoo – to pinpoint 14 possible causes of feeling tired all the time, and reveal how exhaustion affects your health:

14 medical reasons you’re tired all the time

While fatigue is a common symptom of several health conditions, most of the time a good night’s sleep is all it takes for our energy levels to be restored. Here are 14 key reasons why you might feel tired all the time and when to seek help:

1. Burnout

If you feel like you’re permanently running on empty, you could be suffering from burnout. The World Health Organisation (WHO) now recognises burnout as a medical condition, defining it as a syndrome resulting from chronic workplace stress. Burnout develops slowly, and is associated with decreased motivation, a lack of energy, reduced performance, and poor sleep.

‘Sleep is a basic human health behaviour that everybody needs in order to perform during the waking hours,’ says Dr Lederle. ‘All animals show a rest-activity rhythm. Without downtime, the body is unable to repair and restore its functions. What follows are physical and mental illnesses and health problems.’

Work stress and burnout are mutually reinforcing, a study by Johannes Gutenberg Universitaet Mainz found, so addressing it isn’t always straightforward. To combat burnout, delegate tasks at work, take frequent breaks from technology, set aside time for rest and relaxation – yoga, meditation and deep breathing exercises are useful tools – prioritise regular exercise and a healthy diet, and try taking up a creative hobby.

2. Poor diet

One of the biggest culprits of feeling tired all the time relates to your diet. The old adage ‘you are what you eat’ rings true. Refined carbohydrates – like those found in pastries, white pasta and breakfast cereals – cause a rapid rise in your blood sugar levels, and when they inevitably drop, it can leave you feeling extremely tired.

A lack of protein can also impact your energy levels. ‘Protein builds muscle, and lack of muscle causes your metabolic rate to reduce right down – making you feel sluggish and fatigued,’ Jo Gray says. ‘When you’re on a diet of more carbs than protein, a slump in the afternoon can be inevitable as you’re crashing out from sugar.’

Not eating enough food can also leave you feeling drained and impact the quality of your sleep. When you eat too few calories, your metabolism slows down to conserve energy. Follow a healthy, balanced diet and avoid missing meals to keep your engine running. You could also try eating for better sleep by adding some well-timed snacks to your diet.

‘Certain foods trigger the sleep-inducing hormone melatonin,’ says Gray. ‘Foods rich in magnesium – like oats – encourage the production of insulin, which helps neural pathways access tryptophan, an amino acid that acts as a relaxant to the brain. It’s true that a warm glass of milk does help you sleep better. Dairy is a natural source of sleep-inducing tryptophan and the sugar in the dairy provides a great carrier for the amino acid.’

3. Sedentary lifestyle

It’s somewhat ironic, but inactivity can totally drain your energy stores. Leading a sedentary lifestyle can negatively impact sleep quality and make you feel more tired than usual, so it’s important to include exercise in your daily routine. ‘People who exercise infrequently tend to have higher heart rates and lower oxygen consumption than fitter and more active people,’ says Luke Gray –tw0 key factors associated with feeling fatigued.

The good news? Even minimal increases physical activity seem to be beneficial, so the smallest of healthy habits will go a long way. You could do 10 squats when you wake up every morning, swap your office chair for a stability ball, go for a 15 minute walk every lunchtime, and commit to taking phone calls standing up. ‘Get up every hour and move or stretch a little,’ says Dr Lederle. ‘Regular exercise will also help to promote healthy sleep.’

❗How much exercise do you need? The NHS recommends 150 minutes of exercise per week for adults aged 19-64.

4. Vitamin deficiency

If you’re tired all the time, it could be a sign of vitamin deficiency, including low levels of vitamin D, vitamin B-12, iron, magnesium, or potassium:

  • Vitamin D deficiency: Vitamin D is essential for healthy bones and teeth, but research also links a lack of the vitamin with a host of issues, including heart disease, depression, and chronic fatigue syndrome. ‘Vitamin D deficiency is associated with an increased risk in developing sleep disorders,’ says Dr Lederle. ‘High quality supplements may be able to ameliorate this risk.’
  • Iron deficiency: Iron deficiency anaemia is one of the most common medical causes of tiredness, particularly in women who are pregnant or menstruating. Symptoms can include heavy-feeling muscles, heart palpitations and shortness of breath. Your GP should be able to diagnose iron deficiency anaemia using a simple blood test and may prescribe iron supplements.
  • Magnesium deficiency: Magnesium is an essential mineral that is also important for energy production. Key symptoms include feeling tired, muscle cramps, aches and twitches, restless legs and problems sleeping. It’s hard to test for magnesium deficiency but the symptoms are red flags in themselves.
  • Vitamin B12 deficiency: A lack of vitamin B12, also known as folate deficiency anaemia, comes with a wide range of symptoms including muscle weakness, pins and needles, disturbed vision, mouth ulcers, memory problems and depression and can lead to a number of health problems. If you have symptoms seek urgent medical assistance, as some problems caused by B12 deficiency can be irreversible if left untreated.
  • Potassium deficiency: Potassium is a mineral found in the foods you eat that helps your muscles work. Fatigue is often the first sign of potassium deficiency, but common symptoms also include muscular aches and pains, heart palpitations and breathing difficulties. If you are concerned speak to your GP, as potassium deficiency can be linked to a number of serious health issues including hypertension and kidney disease.

???? Vitamin deficiency diagnosis: A routine blood test can help identify a vitamin deficiency. Ask your GP to run a full blood count (FBC) to check for levels of red and white blood cells in the body. A diet overhaul and supplements can make a huge difference with vitamin deficiency. Ask your GP for advice.

5. Stress

Stress is a physical and mental reaction to life’s pressures. Not only has it been shown to adversely affect sleep quality and duration, but insufficient sleep can lead to an increase in stress levels – so it’s easy to get trapped in a cycle of worry. Developing stress management strategies can go a long way towards facilitating a better night’s sleep and restoring your energy levels.

‘Stress is a common trigger of sleep problems, and leaves the body in an aroused state,’ says Dr Lederle. It activates your sympathetic nervous system, triggering the release of stress hormones such as adrenaline and cortisol. Practicing mindfulness can help calm your relaxation response. ‘Daily meditation practices help you to learn ways to step back from worrying thoughts and feelings allowing you to remain calmer,’ she suggests.

To combat stress, keep your caffeine intake in check. ‘A good way to use caffeine is if you’re about to exercise,’ says Jo Gray. ‘When you drink caffeine your cortisol levels increase, which will actually enhance your performance. However, if you are just manually raising this cortisol to give you a boost, sitting at your desk after lunch then you’re not putting that cortisol to good use. Try swapping your afternoon tea for a non-caffeinated hot drink.’

6. Depression

While we tend to think of fatigue primarily as a physical problem, feeling tired all the time is often a key symptom of depression, so it pays to take stock of your mental health. People with depression may also find it difficult to fall asleep and stay asleep during the night.

‘There’s a bidirectional relationship between depression and sleep,’ says Dr Lederle. ‘Having insomnia makes you twice as likely to develop depression.’ If you think you might have insomnia or depression, make an appointment with your doctor.

❗ If you’re struggling to enjoy an uninterrupted night’s sleep and it’s beginning to impact your mental health, try our sleep tips and ask your GP for help.

7. Sleep disorders

Sleep disorders like sleep paralysis, sleepwalking, and sleep apnea affect your ability to get a solid night’s kip. ‘There are over 80 known sleep disorders that affect the duration and quality of sleep,’ says Dr Lederle. ‘This in turn will impact on a person’s ability to function during the day – be that at home or at work, cognitively, physically or emotionally.’

If sleep issues begin to occur on a regular basis and interfere with your day-to-day life, they may indicate a sleep disorder. Sometimes, sleep disorders can be a symptom of another medical or mental health condition, so it’s important to seek out a diagnosis straight away. If you think a sleep disorder could be the reason you’re tired all the time, speak to your GP.

8. Fibromyalgia

Fibromyalgia is a long-term condition characterised by musculoskeletal pain all over the body. As well as making you extremely sensitive to pain – which can be exhausting in itself – fibromyalgia is associated with stiffness, foggy thinking, and often emotional and mental distress.

‘Difficulties sleeping are common symptoms of fibromyalgia,’ says Dr Lederle. ‘It’s linked to insomnia and restless legs syndrome. Finding ways to reduce the pain can help improve sleep.’ If you have concerns about fibromyalgia, consult your doctor.

9. Chronic fatigue syndrome

Also known as ME, chronic fatigue syndrome (CFS) is a long-term illness with a wide range of symptoms that include muscle or joint pain, trouble concentrating, dizziness, and extreme tiredness. ‘Sleep problems including insomnia are common in CFS,’ says Dr Lederle. ‘Many patients with CFS report problems falling or staying asleep.’

‘While the cause of chronic fatigue syndrome is unknown, there are steps you can take to manage the debilitating symptoms and foster a restful night’s sleep. Changes in circadian rhythms might contribute to these sleep problems,’ Dr Lederle adds. ‘Expose yourself to daylight – preferably in the first half of the day – to strengthen your body clock.’

10. Medication

You’re often advised not to operate machinery or drive when taking medicines that are known to make you feel sleepy. But did you know some prescription drugs can keep you up all night? Some list insomnia as a side effect, including high blood pressure and asthma drugs. If you suspect your meds might be the reason you’re feeling tired all the time, check the side effects on the packet and ask your GP or local pharmacist for advice.

11. Food intolerance

When you think about a food intolerance – sensitivity caused by gluten, dairy, or soy, for example – the most typical symptoms tend to include rashes, headaches, nausea and digestive issues like cramp, bloating or diarrhoea. But fatigue, brain fog and low energy levels are just as prevalent in people with an intolerance.

If you suspect you might have a food intolerance, keep a food diary and monitor your symptoms to show your doctor or a dietician. They may suggest eliminating the food for a while and then reintroducing it into your diet in small quantities to assess how much you can eat without experiencing symptoms.

❗ As many as one in two people with type 2 diabetes experience sleep problems, according to the Sleep Foundation.

12. Diabetes

If you feel fatigued, thirsty, can’t stop peeing and have suddenly lost weight, see your GP for a diabetes test. As many as one in two people with type 2 diabetes experience sleep problems, according to the Sleep Foundation. This is due to unstable blood sugar levels and accompanying symptoms, so feeling tired all the time could be a red flag.

‘Diabetes and sleep disturbances are linked,’ agrees Dr Lederle. ‘Both high and low blood sugar levels can impact your sleep. Poor sleep – particularly less deep sleep – can affect insulin levels and potentially contribute to the development of diabetes.’ Diabetes education classes are run in most areas now, to help you manage the condition yourself.

13. Underactive thyroid

Hypothyroidism, also known as underactive thyroid or low thyroid, occurs when your body doesn’t produce enough thyroid hormones. This causes your metabolism to slow down, resulting in a number of telltale symptoms including overwhelming fatigue, lethargy and weight gain.

The good news? By following a thyroid hormone replacement treatment programme, people with hypothyroidism are able to lead completely normal lives. You should see your GP and ask to be tested for an underactive thyroid if you have any symptoms – including slow movements and thoughts, muscle aches, constipation, dry skin, and brittle nails.

14. Post-viral fatigue

If you’re feeling tired after recovering from any kind of viral infection – such as the flu or glandular fever, for example – you might be suffering from post-viral fatigue syndrome. Symptoms can include chronic tiredness, muscle pain, weight loss, vomiting, diarrhoea, a fever or chills, chest pain and shortness of breath.

It’s completely normal to feel wiped out after an illness, but if the symptoms linger for weeks or months and prevent you from leading your life, it’s worth seeking medical advice. Experts don’t fully understand post-viral fatigue, so it’s difficult to treat, but focusing on rest and self-care is a good place to start. People generally get better slowly over time.

❗Can’t work out why you’re tired all the time? While this list will hopefully point you in the right direction, your first port of call should be your GP.

Leave a Reply

Your email address will not be published. Required fields are marked *