Why test for brain fog?
Brain fog describes difficulty concentrating, remembering or thinking clearly. It is not a diagnosis in itself, but it is commonly linked to treatable factors such as low vitamin B12 or folate, an underactive thyroid, low iron stores, poor blood sugar control or low vitamin D. Blood testing can help identify or rule out these physical contributors.
Recommended tests
Vitamin B12 & folate
Compare pricesLow B12 or folate can affect memory, concentration and energy
Thyroid function
Compare pricesAn underactive thyroid commonly slows thinking and causes forgetfulness
Iron profile
Compare pricesLow iron stores can reduce concentration before anaemia develops
Vitamin D
Compare pricesLow vitamin D is common in the UK and linked to tiredness and low mood
When to see your GP
If confusion comes on suddenly, or you notice slurred speech, facial drooping or weakness in an arm or leg, call 999 immediately. For memory problems that are getting worse over weeks or months, speak to your GP.
Why test for brain fog?
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
Not sure where to start?