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Testing & Diagnosis

Blood biomarkers including p-tau

Quick answer

Blood-based biomarkers can indicate Alzheimer's pathology with a simple blood draw.

Author:
Illinois Dementia Guide editorial team
Medically reviewed by:
Amarish Dave, DO, Board Certified Neurologist
Published:
August 2026
Last medically reviewed:
August 2026
Geographic relevance:
Illinois, United States

Overview

Assays such as p-tau217 have improved substantially and are increasingly used in specialty settings, often before deciding whether PET or spinal fluid testing is needed.

Strengths

  • Low burden and widely accessible collection
  • Useful for triage before more invasive testing
  • Improving accuracy in specialty care settings

Limitations

  • Kidney disease, body weight, and other conditions can affect results
  • Not recommended for screening people without symptoms
  • Results should be interpreted by a clinician experienced with memory disorders

Medically reviewed. Last reviewed August 2026. This page is educational information, not individualized medical advice.

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