Always tired? Common causes and tests

Why am I always tired?

Usually because of sleep, stress, diet, activity or a change in your life, and less often because of a physical illness. The NHS lists these as the common causes of tiredness and fatigue:

• not getting enough sleep, or finding it hard to get to sleep (insomnia)
• an unhealthy diet or not getting much exercise
• stress, depression, and life events such as bereavement or looking after a new baby
• hormonal changes, such as during puberty, pregnancy or the menopause
• some illnesses, such as glandular fever and COVID-19
• some medical treatments and medicines, such as chemotherapy

Tiredness is one of the commonest reasons people see a GP. A 2021 review written alongside the German GP guideline on fatigue says it is the main or a secondary reason for 10 to 20% of GP consultations. The most frequent causes of persistent tiredness were sleep problems (including sleep apnoea), depression, which accounted for 18.5% of cases, and stress. Anaemia and other physical causes made up 4.3%, and previously undiagnosed cancer 0.6%. Those figures come from primary care in other countries, but the pattern is a fair guide: look at sleep and mood first, and get checked if the tiredness doesn't add up. If thinking feels slow as well, see our guide to brain fog.

Why am I always tired and sleepy?

If you keep nodding off, the commonest reason is not getting enough sleep. The NHS says adults need 7 to 9 hours on average and that you probably aren't getting enough if you're constantly tired during the day. Our sleep calculator works out bedtimes from the time you need to get up.

If you're sleeping enough hours and still sleepy, two conditions are worth knowing about:

• Sleep apnoea, where your breathing stops and starts while you sleep. The NHS lists loud snoring and gasping, snorting or choking noises at night, and feeling very tired and finding it hard to concentrate during the day. You may not notice the symptoms yourself, so the NHS suggests asking someone to stay with you while you sleep.
• Narcolepsy, which causes sleepiness and difficulty staying awake during the day and falling asleep suddenly. It usually starts in children and young adults.

Why am I always cold and tired?

Feeling cold more than usual alongside tiredness is one of the patterns the NHS describes for an underactive thyroid (hypothyroidism). Its other common symptoms include weight gain, constipation, difficulty concentrating, low mood, dry skin or hair and heavy or irregular periods. They usually come on slowly, which makes them easy to put down to winter or a busy life. A cold house and short nights can do the same thing, so what matters is whether this is new for you. Mention both symptoms to a GP, because a blood test is the way to check your thyroid.

Why am I always hungry and tired?

Irregular meals are the everyday explanation: the NHS suggests eating regular meals and healthy snacks every 3 to 4 hours rather than a large meal less often. If you're eating regularly and still hungry and worn out, two medical causes are worth ruling out:

• Diabetes. Diabetes UK lists increased hunger among the symptoms. The commonest ones, on both the NHS and Diabetes UK lists, are feeling very tired, being very thirsty, peeing more than usual and losing weight without trying.
• An overactive thyroid. The NHS lists feeling tired all the time, difficulty sleeping and weight loss, often despite an increased appetite.

Both are diagnosed with a blood test, and the NHS says not everyone with type 2 diabetes has symptoms. If you think you or your child might have type 1 diabetes, the NHS advises an urgent GP appointment or a call to NHS 111.

Why do I have no energy?

Usually for the same reasons as being tired all the time: too little or poor sleep, an unhealthy diet, little exercise, stress, hormonal changes, or an illness or medicine. Low energy with no motivation or interest in things can also be a symptom of depression. The NHS lists lack of energy and having no motivation or interest in things among its symptoms, and says to see a GP if you've had symptoms of depression for most of the day, every day, for more than 2 weeks. If you've felt flat for a few weeks and can't say why, or it comes with other symptoms such as weight loss or mood changes, see a GP too.

If you ever feel you might harm yourself, call 999 or go to A&E. You can call NHS 111 at any time, or Samaritans free on 116 123.

When should you see a GP about tiredness?

The NHS says see a GP if you've been tired for a few weeks and don't know why, if it's affecting your daily life, or if you're tired and have other symptoms, such as weight loss or mood changes, or you've been told you gasp, snort or choke in your sleep. The NHS also says not to diagnose yourself from a list of symptoms.

What blood tests will a GP do for tiredness?

That depends on your symptoms. The NHS says you may need blood tests to check for anaemia, diabetes or an overactive thyroid, and a blood test is also how an underactive thyroid is found. NICE lists unexplained fatigue among the common symptoms of vitamin B12 deficiency, so a GP may test B12 too, particularly if you eat little or no animal food or take metformin or stomach acid medicines called proton pump inhibitors. The German review advises that simple blood tests are enough unless other symptoms or findings point somewhere specific. If they come back normal, regular follow-up is better than a hunt for rare causes.

Beyond tests, a GP may suggest talking therapy such as CBT, advice on sleep or lifestyle changes, or refer you to a specialist.

What helps if you're tired all the time?

The NHS self-help advice covers most of the ground:

• Keep the same sleep times every day, with no caffeine, food or exercise in the couple of hours before bed and no screens in the last hour.
• Move more. The NHS says even a single 15-minute walk can give you an energy boost, building up over weeks to 2 hours 30 minutes of moderate activity a week.
• If you cut down on caffeine, do it gradually, because stopping suddenly can cause insomnia and headaches.
• Drink less alcohol. You fall asleep more easily but sleep less deeply, and the NHS says you'll be tired the next day even after a full 8 hours.
• Have a glass of water. The NHS says sometimes you feel tired simply because you're mildly dehydrated.

If your tiredness gets worse for hours or days after you do more, tell your GP before you push on. That pattern, called post-exertional malaise, is a feature of ME/CFS.

Which vitamins are best for tiredness and fatigue?

Nine nutrients carry an authorised GB health claim that they contribute to the reduction of tiredness and fatigue: folate, iron, magnesium, niacin, pantothenic acid, riboflavin, vitamin B6, vitamin B12 and vitamin C. The claims are real, but they don't mean extra gives you more energy. Your body needs these nutrients to release energy and carry oxygen, and running short of one can make you tired. If you already have enough, taking more isn't expected to help.

A trial of iron shows how this works. In 2003, Swiss researchers gave 144 women with unexplained tiredness, none of them anaemic, either iron or a placebo for four weeks. Fatigue fell by 29% on iron and 13% on placebo, but only the women with low or borderline iron stores (ferritin of 50 µg/L or less) improved. The NHS says most people get all the nutrients they need from a varied and balanced diet. The people more likely to be short are covered in our guides to signs of low iron, B12 deficiency and B vitamins.

Some people are more likely to be short. The NHS says women who lose a lot of blood in heavy periods are at higher risk of iron deficiency anaemia. For vitamin B12, it says the commonest cause of deficiency in the UK is pernicious anaemia, that a vegan diet can cause it if you don't take B12 supplements, and that some medicines, including proton pump inhibitors, can reduce absorption. A B12 or folate deficiency can cause extreme tiredness and a lack of energy. The NHS says to see a GP if you think you may have one, and that diagnosis is usually based on symptoms and a blood test.

Higher doses carry their own risks. These are the NHS amounts for adults, and the most it says you can take from supplements without likely harm:

Iron is the one not to guess at, because some people, such as those with the inherited condition haemochromatosis, already have too much. Get a blood test before taking it.

Do vitamins and energy supplements give you energy?

Not directly. The authorised claim is that nine nutrients contribute to the reduction of tiredness and fatigue, and that matters if you're short of one. Vitamins and minerals help your body use the energy in food, and if you already have enough, taking more isn't expected to help. Some energy supplements and drinks also contain caffeine. The NHS advises no caffeine in the couple of hours before sleep, and poorer sleep can leave you more tired. Our caffeine calculator shows how your day adds up. If you've been tired for a few weeks with no clear reason, see a GP before trying supplements, because a blood test can show whether you're short of iron or B12.

Where Natura fits

Daily Iron (iron 14 mg as bisglycinate), Daily B12 (vitamin B12 1000 µg as fermented methylcobalamin) and Daily Magnesium (magnesium 200 mg as glycinate) are in the Natura cabinet (coming soon) with the daily bottles, and the iron and B12 also come together in the Blood Pack. Iron and vitamin B12 contribute to the reduction of tiredness and fatigue, and magnesium contributes to a reduction of tiredness and fatigue, but they're only worth taking if you're short, so get a blood test first, especially for iron. The same nutrients appear in several Natura products, so add up everything you take: Daily Iron with the Blood Pack or Core Pack comes to 28 mg of iron, over the NHS 17 mg, and Daily Magnesium with the Kidneys Pack comes to 500 mg of magnesium, over the NHS 400 mg. Daily B12 is also in the B Pack and Ears Pack, and magnesium is in Daily Electrolytes and the Sleep, Calm and Core packs.