B12 and Folate Test
Check your vitamin B12 and folate levels with a simple home fingerstick test. Ideal for vegans, those on metformin.
£39.00
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Overview
What Is Fatigue?
Fatigue is more than ordinary tiredness — it is a persistent, often overwhelming lack of energy that fails to improve with adequate sleep or rest. It is one of the most common reasons people visit their GP in the UK, yet its root cause is frequently missed without targeted blood testing.
At a cellular level, fatigue often reflects a failure in energy production. Iron, for example, is required for haemoglobin synthesis, which carries oxygen to tissues. When ferritin (iron stores) falls below optimal levels, oxygen delivery drops and every cell in the body becomes less efficient — the result is the deep, physical tiredness many people describe as bone-deep exhaustion. Similarly, thyroid hormones regulate the metabolic rate of every cell; an underactive thyroid slows energy production system-wide.
Fatigue becomes a clinical concern when it persists for more than four weeks, interferes with daily activities, or is accompanied by other symptoms such as weight change, mood disturbance, or cognitive difficulties. A structured blood panel can identify the majority of reversible biochemical causes within a single test session, making early investigation both practical and cost-effective.
Tired vs. Fatigued: there is a difference
Ordinary tiredness resolves after a good night's sleep; fatigue persists regardless of how much rest you get. If your exhaustion is unrelenting and unrefreshing, a biochemical cause is worth ruling out.
Related experience
Common Symptoms Associated With Fatigue
Fatigue rarely occurs in isolation — it commonly appears alongside other symptoms that point toward the same underlying imbalance.
The big picture
What Causes Fatigue?
Fatigue has many potential causes — from nutritional deficiencies and hormonal imbalances to chronic conditions and lifestyle factors.
What to measure
Biomarkers Associated With Fatigue
These blood markers are most commonly implicated in fatigue and form the basis of a thorough energy investigation.
Underlying causes
Conditions Associated With Fatigue
Several diagnosable conditions commonly present with fatigue as their primary or most prominent symptom.
Getting answers
How Fatigue Is Investigated
Investigating persistent fatigue typically follows a structured approach to identify the most likely reversible causes first.
1
Medical history
Your clinician will ask about the duration, severity, and pattern of your fatigue, alongside any associated symptoms such as weight change, cold intolerance, or mood disturbance.
2
Lifestyle review
Sleep quality and quantity, diet, alcohol intake, physical activity levels, and current stress are all assessed, as lifestyle factors alone can cause or compound fatigue.
3
Blood testing
A targeted blood panel checks iron stores (ferritin), thyroid function (TSH, Free T4), key vitamins (B12, D, folate), blood sugar (HbA1c), sex hormones, and inflammatory markers to identify biochemical causes quickly.
4
Specialist referral
If initial tests are inconclusive or a condition such as sleep apnoea, autoimmune disease, or chronic fatigue syndrome is suspected, your GP may refer you to a specialist for further evaluation.
Recommended testing
Recommended Blood Tests
Private blood tests analysed by UK-accredited laboratories, with clear results and optional GP review.
Vitamin D Test
Measure your 25-OH vitamin D level with a simple home fingerstick kit. Results reviewed by a GMC-registered physician and returned in 3 to 5 working days.
£29.00
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Essential Vitamin and Mineral Panel
Check your levels of vitamin D, B12, folate, ferritin, and zinc in one convenient test. Home fingerstick kit available. GMC physician review included.
£79.00
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Comprehensive Nutritional Panel
An in-depth 12-marker nutritional screen covering fat-soluble vitamins, B vitamins, key minerals, homocysteine, and omega-3 index.
£149.00
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PCOS Hormone Panel
A targeted nine-marker hormonal and metabolic screen designed to assess the key features of polycystic ovary syndrome — including androgens.
£109.00
View test
Everyday contributors
Lifestyle Factors That Can Contribute
Several everyday lifestyle factors can directly cause or significantly worsen fatigue, often alongside a biochemical imbalance.
Poor sleep
Too little or broken, unrefreshing sleep
High stress
Chronic stress keeps the body in overdrive
Alcohol
Disrupts sleep quality and recovery
Poor diet
Low in iron, protein and key nutrients
Overtraining
Too much exercise without adequate recovery
Sedentary lifestyle
Deconditioning lowers daily energy
Safety first
When To Seek Medical Advice
Most fatigue has a benign cause, but certain accompanying symptoms should prompt prompt medical attention.
Red flags — speak to a doctor
These can point to a more serious underlying cause and should not be ignored.
- Unexplained weight loss alongside persistent fatigue
- Fatigue with chest pain, palpitations, or shortness of breath
- Severe or rapidly worsening weakness
- Fatigue with night sweats, swollen lymph nodes, or fever
Common questions
Frequently Asked Questions
Yes — iron deficiency is one of the most common reversible causes of fatigue in the UK. Iron is essential for the production of haemoglobin, the protein in red blood cells that carries oxygen to every tissue in the body. When ferritin (your iron stores) is low, oxygen delivery falls and cells cannot generate energy efficiently. Women of reproductive age and athletes are particularly at risk. A simple ferritin blood test can confirm whether iron deficiency is contributing to your fatigue.
A thorough fatigue screen should include ferritin (iron stores), TSH and Free T4 (thyroid function), vitamin B12, vitamin D, folate, HbA1c (blood sugar), and CRP (inflammation). In men, total testosterone is also worth checking. Trupoint Health’s Energy & Fatigue Screen covers these key markers in a single at-home blood draw.
Fatigue that persists despite adequate sleep is a hallmark sign that a biochemical rather than behavioural cause is at play. The most common culprits include iron deficiency, hypothyroidism, vitamin D deficiency, and low testosterone. Sleep disorders such as obstructive sleep apnoea can also cause unrefreshing sleep even when time in bed seems sufficient. A blood test is the logical first step to rule out these correctable causes.
Yes — hypothyroidism (underactive thyroid) is a classic and frequently overlooked cause of persistent fatigue. Thyroid hormones regulate metabolism across every cell in the body; when thyroid output falls, cellular energy production slows, producing profound tiredness, cold intolerance, weight gain, and cognitive dulling. A TSH blood test is the standard screening tool and is included in most fatigue panels.
Yes — cortisol imbalance is a recognised but often overlooked cause of fatigue. Cortisol should be highest in the morning to drive alertness and taper through the day. Chronic stress can flatten this rhythm, leaving you exhausted in the morning and wired at night. An adrenal dysfunction screen including morning cortisol can identify this pattern.
Keep exploring
Related Symptoms
Related Biomarkers
Related Conditions
Sources
References
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NHS — View source
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NICE — View source
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British Thyroid Foundation — View source
This page is for general information only and does not replace personalised medical advice. If you are worried about your health, please speak to a qualified healthcare professional. Trupoint Health blood tests are analysed by UK-accredited laboratories.