Why test for fatigue?
Fatigue is one of the most common reasons people seek blood tests. It can stem from iron deficiency, underactive thyroid, vitamin D or B12 deficiency, diabetes, or hormonal imbalances. A targeted blood test can identify — or rule out — the most frequent underlying causes, giving you a clear direction for treatment.
Recommended tests
Full blood count
Compare pricesScreens for anaemia and infection markers that commonly cause fatigue
Thyroid function
Compare pricesHypothyroidism is a leading cause of unexplained tiredness
Iron profile
Compare pricesIron deficiency is the most common nutritional deficiency worldwide
Vitamin D
Compare pricesLow vitamin D is extremely common in the UK and linked to fatigue and muscle weakness
Vitamin B12 & folate
Compare pricesDeficiency causes fatigue, brain fog, and neurological symptoms
When to see your GP
If your fatigue is accompanied by unexplained weight loss, persistent fever, or has lasted more than four weeks without improvement, consult your GP.
Why test for fatigue?
Symptom-led matching
See the tests commonly used to investigate this symptom
UKAS accredited labs
Every listed provider uses UKAS-accredited UK laboratories
Clear turnaround
Typical result times shown alongside price and biomarker coverage
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