Feeling constantly tired? You’re not alone.
There are many valid reasons why we might feel tired or fatigued — and yes, sometimes we just need rest.
However, if tiredness becomes constant and stops you from enjoying life, it’s worth looking deeper. Chronic fatigue can be your body’s way of signalling that something isn’t quite right.
Here are five surprising causes of persistent tiredness — and simple steps you can take to start feeling more energised again.
1. Mitochondrial Decline as You Age
Ageing is often blamed for fatigue — but the real reason may be linked to your mitochondria, the tiny “powerhouses” in your cells that produce energy.
As we get older, both the number and efficiency of mitochondria decline. The good news? You can support them through lifestyle and nutrition.
What to do:
✅ Eat real, unprocessed foods
✅ Include good-quality fats (avoid refined seed oils)
✅ Enjoy a wide variety of mineral- and vitamin-rich foods
✅ Move daily — gentle movement keeps mitochondria active
Small daily choices make a big difference in maintaining your cellular energy.
2. Not Taking Enough Breaks During the Day
It might sound counterintuitive, but taking short breaks can increase your productivity and energy.
Constant busyness raises stress hormones, eventually leading to exhaustion.
What to do:
💡 Take 5 minutes to pause and breathe deeply
💡 Stand barefoot on grass or step outside for fresh air
💡 Meditate, stretch, or simply sit quietly
💡 Spend mindful moments in nature
These “mini pauses” reduce stress hormones and boost focus — turning busyness into true productivity.
3. Thyroid Function Imbalance
Thyroid issues are a common but often overlooked cause of fatigue.
Conditions like underactive thyroid (hypothyroidism) or autoimmune Hashimoto’s can make you feel drained — even when your blood test results seem “normal.”
Standard tests usually measure only TSH (Thyroid Stimulating Hormone), which doesn’t show the full picture.
What to do:
🧠 Ask your GP or practitioner for a full thyroid panel — including Free T3, Free T4, and Reverse T3
🧠 Ensure you get enough selenium and zinc — they’re crucial for hormone conversion
🧠 Work with a Nutritional Therapist who specialises in thyroid health for tailored support
A deeper look at thyroid function can often explain long-term tiredness.
4. Blood Sugar Imbalance
You don’t have to be diabetic to experience energy crashes caused by blood sugar fluctuations.
For some people, even foods like oats or bread can cause sharp spikes and drops — leaving you feeling tired and craving sugar.
What to do:
🍞 Ask your GP for a fasting glucose and HbA1c test
🍞 Use a continuous glucose monitor (CGM) or diabetic test strips to check how foods affect you
🍞 Notice how certain meals impact your energy — stable blood sugar = stable energy
Balancing your blood sugar can be life-changing for fatigue and focus.
5. Food Intolerances or Sensitivities
If your immune system is constantly reacting to certain foods, even mildly, it uses up precious energy.
Unlike allergies (which cause immediate reactions), food sensitivities can take hours or days to show — making them tricky to detect.
For example:
You might react to coffee and a doughnut together, but not to either one alone.
Or small amounts of a food might be fine — until you have too much.
What to do:
🥗 Keep a food and symptom diary for a few weeks
🥗 Consider food intolerance testing with a qualified Nutritional Therapist
🥗 Eliminate or reduce trigger foods, then reintroduce slowly to identify sensitivities
Pinpointing and addressing hidden food reactions can dramatically improve your energy levels.
The Bottom Line: Don’t Ignore Persistent Fatigue
Tiredness is not something you should simply “live with.”
It’s your body’s way of saying something needs attention.
Start by visiting your GP to rule out medical causes, then consider working with a Nutritional Therapist who can explore deeper imbalances — from thyroid health to nutrient deficiencies and food sensitivities.
Addressing fatigue early helps you feel like yourself again — and can prevent more serious issues down the road.
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