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Why Am I Always Tired? Key Blood Tests to Identify the Root Cause
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Why Am I Always Tired? Key Blood Tests to Identify the Root Cause

Levitas DX
6 April 2026
7 min read

Levitas Diagnostics | London (Mayfair, Knightsbridge, Kensington) & Surrey (Guildford, Esher)

Feeling constantly tired is one of the most common yet most misunderstood symptoms in modern healthcare. 

At Levitas Diagnostics, we see patients daily who have been told: 

“Your blood tests are normal.” 

  • PPersistent fatigue
  • PBrain fog
  • PLow motivation
  • PPoor recovery

The reality is simple: 
Standard testing often misses the root cause. 

If you’re searching for answers through blood tests for fatigue, this guide will show you how advanced fatigue testing in the UK can uncover what conventional medicine overlooks. 

Why Am I Always Tired? The Real Causes

Fatigue is rarely caused by one issue alone. It is usually a combination of: 

Mitochondrial dysfunction

Nutrient deficiencies

Hormonal imbalance

Chronic inflammation

Neurotransmitter disruption

At Levitas, we approach fatigue as a multi-system imbalance, not just a symptom. 

The Problem with Standard Testing

Basic NHS or routine panels often include:

  • Full blood count 
  • Thyroid (limited markers) 
  • Basic iron levels 

While useful, they do not assess:

  • Cellular energy production 
  • Micronutrient status 
  • Neurotransmitter balance 
  • Functional deficiencies 

This is why many patients with chronic fatigue are left without answers. 

Key Blood Tests for Fatigue (Advanced Approach)

Micronutrient Test for Low Energy

Your body depends on vitamins and minerals to produce energy. 

Key Nutrients Assessed 
  • B vitamins (especially B12, B6, folate) 
  • Magnesium 
  • Zinc 
  • Vitamin D 
Why It Matters 

Even mild deficiencies can lead to: 

  • Fatigue 
  • Brain fog 
  • Poor recovery 

At Levitas, we use advanced micronutrient testing to assess intracellular levels—not just serum values. 

Essential Minerals Blood Test

Minerals are the electrical conductors of the body. 

Low levels can disrupt
  • Muscle function 
  • Nerve signalling 
  • Energy production 
Common Symptoms 
  • Fatigue 
  • Weakness 
  • Poor sleep 
  • Muscle tension 

Iron Support Test for Tiredness

Iron is critical for oxygen transport. 

Beyond Basic Iron 

We assess

  • Ferritin (storage iron) 
  • Transferrin saturation 
  • Total iron-binding capacity 
Why It Matters 

Low iron—even within “normal” ranges—can cause: 

  • Chronic tiredness 
  • Breathlessness 
  • Reduced stamina 

CoQ10 Test for Fatigue

CoQ10 is essential for mitochondrial energy production. 

Think of CoQ10 as

The spark plug of your cellular engine 

Low levels can result in

  • Severe fatigue 
  • Muscle weakness 
  • Poor endurance 

This is particularly relevant for

  • Patients on statins 
  • Individuals with chronic fatigue syndromes 

Neurotransmitter Test for Fatigue

Energy is not just physical—it is neurological. 

Key Neurotransmitters 
  • Dopamine (motivation) 
  • Serotonin (mood) 
  • GABA (calmness) 
Symptoms of Imbalance 
  • Low motivation 
  • Mental fatigue 
  • Poor focus 

At Levitas Diagnostics, we explore brain chemistry as part of fatigue assessment. 

Hormonal and Metabolic Testing

Fatigue is often linked to hormonal imbalance. 

Key Areas 
  • Thyroid (full panel, not just TSH) 
  • Cortisol (stress hormone) 
  • Testosterone / DHEA 
Why It Matters 

Hormonal dysregulation can: 

  • Drain energy 
  • Disrupt sleep 
  • Affect mood and drive 

Chronic Fatigue Diagnosis: A New Perspective

Chronic fatigue is not a single disease—it is a signal. 

At Levitas, we redefine chronic fatigue diagnosis as: 

“Understanding where the system has lost efficiency.” 

This includes: 

  • Energy production 
  • Nutrient availability 
  • Hormonal balance 
  • Detox pathways 

Advanced Fatigue Testing UK: The Levitas Approach

If you are searching for advanced fatigue testing in the UK, our approach is different. 

We Focus On :

  • Root-cause diagnostics 
  • Functional and cellular testing 
  • Personalised interpretation 

Our Locations

We offer testing across: 

London: Mayfair, Knightsbridge, Kensington, Chelsea, Marylebone, Belgravia 
Surrey: Guildford & Esher 

What Happens After Testing?

Testing is only the beginning. 

We create a personalised plan that may include: 

Nutritional optimisation 

Targeted supplementation 

Hormonal balancing 

Lifestyle interventions 

At Levitas, we aim to: 

Restore energy—not just explain fatigue. 

FAQs: Blood Tests for Fatigue

1. What are the best blood tests for fatigue?

A combination of micronutrient, iron, hormonal, and mitochondrial markers provides the most insight. 

2. Why do I feel tired even if my blood tests are normal?

Standard tests often miss functional deficiencies and cellular imbalances.

3. What is advanced fatigue testing in the UK?

It includes deeper analysis of nutrients, hormones, and cellular energy markers. 

4. Can a micronutrient test help low energy?

Yes, deficiencies in vitamins and minerals are a common cause of fatigue. 

5. What is a CoQ10 test for fatigue?

It measures levels of a key molecule involved in energy production within cells. 

6. How does iron affect tiredness?

Low iron reduces oxygen delivery, leading to fatigue and low stamina. 

7. What is included in an essential minerals blood test?

Magnesium, zinc, and other key minerals that support energy and nerve function. 

8. Can neurotransmitter testing explain fatigue?

Yes, imbalances can affect motivation, focus, and mental energy. 

9. Is fatigue linked to hormones?

Absolutely—thyroid, cortisol, and testosterone all play key roles. 

10. How accurate are fatigue blood tests?

Advanced testing provides a much clearer picture than standard panels. 

11. Where can I get fatigue testing in London?

Levitas Diagnostics offers testing in Mayfair, Knightsbridge, and surrounding areas. 

12. Is fatigue always due to one cause?

No, it is usually multifactorial. 

13. Can these tests help chronic fatigue syndrome?

They can help identify contributing factors and guide personalised treatment. 

14. How long does it take to get results?

Typically within a few days to a couple of weeks, depending on the test. 

15. What happens after testing?

You receive a personalised plan to restore energy and optimise health. 

16. Is testing available in Surrey?
17. Do I need a referral?

No, you can book directly with Levitas Diagnostics. 

18. Can fatigue be reversed?

In many cases, yes—when the root cause is identified and addressed. 

Final Thoughts

Fatigue is not something you should “just live with.” 

It is your body’s way of saying: 

“Something needs attention.” 

At Levitas Diagnostics, we go beyond surface-level testing to uncover the true drivers of low energy. 

Whether you are in London (Mayfair, Knightsbridge, Kensington, Chelsea, Marylebone, Belgravia) or Surrey (Guildford, Esher), our team is here to guide you towards clarity, energy, and long-term vitality. 

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