Alzheimer's blood test could 'revolutionise' diagnosis

More than 1,000 people across the UK with suspected dementia are to be offered a blood test for Alzheimer's disease which it is hoped could revolutionise diagnosis of the disease.

The blood test can detect biomarkers for rogue proteins which accumulate in the brains of patients with the condition and will be used in addition to pen and paper cognitive tests, which often misdiagnose it in its early stages.

Scientists leading the trial at University College London believe the blood test will improve the accuracy of diagnosis from 70% to more than 90% and want to see how that helps patients and clinicians.

Patients will be recruited at 20 memory clinics as part of the study, which aims to see how well the test works within the NHS.

The new blood test, which costs around £100, measures a biomarker called p-tau217, which reflects the presence of both proteins.

Previously, the only way to confirm Alzheimer's was by specialist PET brain scans and lumbar punctures to extract cerebrospinal fluid.

However, these "gold standard" tests are not part of routine Alzheimer's diagnosis and only 2% of patients ever receive them.

Professor Fiona Carragher, chief policy and research officer at the Alzheimer's Society, said: "Our recent Lived Experience Survey revealed that only a third of people with dementia felt their experience of the diagnosis process was positive, while many reported being afraid of receiving a diagnosis.

"As a result, too often, dementia is diagnosed late, limiting access to support, treatment and opportunities to plan ahead."

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Source: BBC News, 9 September 2025