It’s not just how busy you are or how much sleep you’re getting, there could be a medical reason for feeling sluggish

Tired woman

Feeling slugging isn’t always caused by lack of sleep © iStock

‘Why am I tired?’ is a question many of us ask ourselves. Below, we reveal different reasons you might be feeling sluggish.

Your Diet

Too many processed carbohydrates (such as bread, pizza, biscuits, cake, pasta, pies…) can contribute to your tired feeling by altering your gut flora and interfering with your colon’s production of B vitamins, which are essential for energy in every cell in the body. ‘Tea, coffee and sugar also overwork the adrenal glands,’ explains nutritional consultant Judy Watson.

Other symptoms: Feeling run-down and bloated.

How to fix it: ‘Try to eat as cleanly as possible – with little or no processed foods, and plenty of green veg, protein and healthy oils (from nuts and seeds) to preserve your adrenals,’ says Judy. Take B complex and vitamin-C supplements, and consider a good-quality probiotic (eg, Bio-Kult) to restore your gut flora.

Adrenal Fatigue

Your adrenal glands pump out stress hormone cortisol, to keep you alert and get you going. But too much stress – whether due to a big life event, like the loss of a loved one, or the ongoing demands of a highly charged job – can cause you to produce too much, putting more strain on the adrenals than they can cope with.

Other symptoms: You feel unhappy, irritable and constantly exhausted, needing to prop yourself up with stimulants such as coffee, cola and tea.

How to fix it: Adrenal fatigue is more likely to be treated by a naturopath or nutritional therapist than a GP. You could also try practising daily meditation to calm your system, eating five small high-protein meals a day (such as eggs, prawns or a chicken salad) to boost energy, and ‘burning off’ excess cortisol by doing regular exercise.

Type 2 Diabetes

Being overweight is a risk factor, as is being over 40 years old (25 if you’re Asian), explains Dr Tony Steele, a GP and clinical director of ‘There’s also a higher risk if you have a close relative with the condition, or if you’re of South Asian, Chinese, African-Caribbean or black African origin.’

Other symptoms: Feeling unnaturally thirsty and needing the loo more often.

How to fix it: Type 2 diabetes is diagnosed via a blood test. ‘Treatment involves careful monitoring of weight, diet and physical activity,’ says Dr Steele. ‘By getting your weight to a healthy level, eating well and exercising, you may be able to keep your glucose (sugar) levels safe. If not, sugar-lowering tablets may be prescribed and, in some cases, insulin.’

Underactive Thyroid

Your thyroid gland, found at the front of your neck, produces hormones that regulate your metabolism. But if it becomes underactive, everything slows down – including your energy levels. ‘Most cases are caused by the immune system attacking the thyroid gland and damaging it,’ explains Dr Steele.

Other symptoms: Gaining weight and feeling depressed. You may also be sensitive to the cold, and your hair and skin may be dryer than usual.

How to fix it: The only accurate way of finding out whether you have a thyroid problem is via a blood test, so see your GP. ‘Early diagnosis is important,’ says Dr Steele. ‘Treatment – with daily hormone tablets (levothyroxine) to replace the hormones that your thyroid’s not making – usually works quickly, and symptoms are soon alleviated. But be prepared to take the drugs for the rest of your life.’


A recent GP survey found that one in five patients complaining of fatigue were in fact dehydrated. When you’re not getting enough fluids, your blood volume is reduced and your heart has to work extra hard to pump blood round the body.

‘We’re made up of 70% water, and everything from your brain to your muscles relies on it,’ says Judy. ‘Coffee and alcohol are diuretics and dehydrate the body, so alternating these drinks with water is essential.’

Other symptoms: As well as feeling tired, you may actually feel quite weak. Your urine is likely to be dark instead of pale yellow; and when you pinch the skin on the back of your hand, it’s slow to spring back.

How to fix it: ‘Try to eat at least five portions of fruit and vegetables daily (they’ll contribute to your fluid intake) and aim to drink 200ml of water every hour for 10 hours a day,’ says Judy.


This condition is the result of too few red blood cells – or too little haemoglobin in them – which are vital for carrying oxygen around the body.

‘It’s actually one of the most common reasons for feeling constantly tired and affects one in 20 post-menopausal women, but it’s even more common in women who are still having periods (particularly heavy ones) and expectant mums,’ says Dr Steele.

Other symptoms: Your fatigue is accompanied by a feeling of general inertia and your muscles may feel heavy.

How to fix it: It’s important to be diagnosed by your GP (again, it will involve a blood test), so don’t hazard a guess or self-treat with iron supplements, as they can be dangerous if taken without medical supervision.

Besides supplements (if recommended), you can also help yourself with a diet packed with iron-rich foods, such as eggs, meat, fish, tofu, pulses, beans, brown rice, nuts, seeds, dark green leafy veg, and even iron-fortified cereals and bread.

Magnesium Deficiency

A study at New York Headache CenteR found that 50% of migraine sufferers had low magnesium levels. Stress can be a symptom and a cause of magnesium deficiency, so stress and any of the symptoms explained below are good reasons to look at your diet.

Other symptoms: Agitation and anxiety, nausea, abnormal heart rhythms, muscle spasms and weakness, poor nail growth, and even hyperventilation and seizures.

How to fix it: Magnesium is best absorbed through the skin, so a good way to top up is to add two cups of Epsom salts to your bath for a 15- minute soak. Also look at your diet, says Judy.

‘A diet high in sugar and alcohol depletes magnesium, but eating more greens, beans and nuts will help to retain it.’