Energy, Fatigue and Tiredness Health Checks and Blood Tests

Low energy and persistent fatigue are among the most common reasons people seek medical advice. While tiredness is often related to lifestyle, it can also be associated with underlying health conditions, nutritional deficiencies, hormone imbalances, or metabolic disorders. Blood testing can help identify potential causes and guide the next steps.

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Advanced Vitamin B12 Blood Test

Get detailed insights into your vitamin B12 levels, including active B12 markers, to understand the root causes of low energy, mood changes, and cognitive difficulties

  • Results estimated in 3 working days
  • 18 biomarkers
£89.00
Epstein-Barr Virus Antibodies Blood Test

Check for antibodies to the virus that causes glandular fever

  • Results estimated in 5 working days
  • 3 biomarkers
£109.00
Epstein-Barr Virus (EBV DNA) Blood Test

Check for the presence of glandular fever with our simple blood test

  • Results estimated in 7 working days
  • 1 biomarkers
£299.00
Energy Essentials Blood Test

Feeling rundown? Our Energy Essentials Blood Test is designed to help uncover some of the most common causes of fatigue, including vitamin deficiencies and thyroid conditions

  • Results estimated in 2 working days
  • 3 biomarkers
£74.00
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“There's a wide variety of causes for low energy and persistent tiredness. Our range of tests helps uncover potential contributors such as anaemia, nutrient deficiencies, hormone imbalances, and, less commonly, Lyme disease.”

Dr Tina Ghela, Head of Clinical, Medichecks

Which energy blood test should I choose?

The best test depends on your symptoms and how comprehensive you want your assessment to be.

What can cause low energy?

Feeling tired all the time doesn't always have a single cause. Fatigue can develop for many reasons, and several factors often contribute simultaneously.


Common causes include:

  • Iron deficiency or anaemia
  • Low vitamin B12, folate, or vitamin D
  • An underactive thyroid
  • Diabetes or poor blood glucose control
  • Liver or kidney disease
  • Hormone imbalances
  • Poor sleep, stress, or overtraining
  • Some medications


If you've been feeling persistently tired for several weeks or your symptoms are affecting your daily life, blood testing can help identify whether an underlying medical condition should be investigated.

FAQs

Can blood tests diagnose chronic fatigue syndrome?

Chronic fatigue syndrome (CFS/ME) is a clinical diagnosis based on your symptoms, medical history, and the exclusion of other conditions.


There isn't a single blood test that can diagnose CFS/ME. However, blood tests play an important role in ruling out other causes of persistent fatigue, many of which can produce similar symptoms.

Why am I always tired?

Persistent tiredness can have many causes, including poor sleep, stress, nutritional deficiencies, thyroid disorders, diabetes, hormone imbalances, anaemia, infections, and chronic medical conditions. Blood tests can help identify or rule out many of these possibilities.

What's the best blood test for fatigue?

Our Energy Essentials Blood Test focuses on some of the most common contributors to tiredness, while individual vitamin and thyroid tests can help if you're following up on a particular concern or monitoring an existing condition.

If you're looking for a broad assessment, the Optimal Health Blood Test is one of our most comprehensive tests, measuring a wide range of biomarkers associated with fatigue, including iron status, vitamin levels, thyroid function, inflammation, liver and kidney health, and blood glucose.

Can a vitamin deficiency make you tired?

Low levels of iron, vitamin B12, folate, and vitamin D are common causes of fatigue and reduced energy. Blood testing can confirm whether a deficiency is present.

Can thyroid problems cause tiredness?

Yes. An underactive thyroid (hypothyroidism) commonly causes fatigue, low energy, weight gain, dry skin, and feeling cold. A thyroid blood test can assess whether your thyroid may be contributing to your symptoms.

When should I have a blood test for fatigue?

If you've been feeling unusually tired for several weeks, your symptoms are persistent or worsening, or they're affecting your work or daily life, it's worth discussing your symptoms with a healthcare professional. Blood testing can often help identify common medical causes.

What if my blood test is normal, but I'm still tired?

Normal blood test results don't necessarily explain every cause of fatigue. Sleep disorders, mental health, chronic fatigue syndrome, medications, lifestyle factors, and other medical conditions may also contribute, so further assessment may sometimes be needed.