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Testing & Diagnosis

Alzheimer's biomarkers

Quick answer

Biomarkers detect the biology of Alzheimer's disease rather than only its symptoms.

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

Biomarker testing is appropriate when the result would change management — for example, when disease-modifying therapy is being considered or the diagnosis is uncertain.

Available approaches

  • Blood-based tests including p-tau217
  • Cerebrospinal fluid amyloid and tau
  • Amyloid PET imaging
  • Tau PET in selected settings

Important cautions

  • A positive amyloid result does not by itself explain every symptom
  • Testing is generally not appropriate for people without symptoms outside research
  • Insurance coverage varies and should be verified in advance

Related resources

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

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