Neurology

Alzheimer’s Disease: Overview

A practical overview of Alzheimer’s disease: symptoms, diagnosis, biomarkers, staging, and what treatments can and can’t do today.

2 min read

Summary

Alzheimer’s disease is a neurodegenerative condition and the most common cause of dementia. It affects memory, thinking, and daily function over time.

This guide covers:

  • what Alzheimer’s is (and what it isn’t)
  • common symptoms and progression
  • how diagnosis is made
  • the role of biomarkers (amyloid, tau, blood tests)
  • treatment options and practical planning

What is Alzheimer’s disease?

Alzheimer’s disease is associated with abnormal brain protein pathology (commonly described as amyloid plaques and tau tangles) alongside progressive neurodegeneration. Symptoms usually develop gradually and worsen over years.

Symptoms

Typical early symptoms include:

  • short-term memory problems
  • difficulty finding words
  • getting lost in familiar places
  • changes in executive function (planning, organization)

As the disease progresses, symptoms can include:

  • loss of independence in daily tasks
  • behavioral or personality changes
  • language and visuospatial problems

Diagnosis

Diagnosis commonly involves:

  • clinical history (including collateral history from family)
  • cognitive assessment
  • neurological examination
  • blood tests to rule out other causes
  • brain imaging when needed
  • biomarker testing in selected settings

Biomarkers and staging

Modern frameworks describe Alzheimer’s as a clinical-biological condition:

  • Biomarkers can indicate the presence of Alzheimer’s pathology.
  • Symptoms and function determine clinical stage and day-to-day impact.

Blood-based biomarkers are increasingly used to support diagnostic workups in appropriate clinical contexts.

Treatment and management (current reality)

Management typically includes:

  • symptom-focused medications when appropriate
  • risk reduction and comorbidity management
  • practical supports and planning (safety, driving, finances)
  • caregiver support

In some settings, disease-modifying therapies for early Alzheimer’s may be available, with eligibility determined by clinical stage and biomarker evidence.

FAQ

Is Alzheimer’s disease the same as dementia?

No. Dementia is a syndrome (a set of symptoms). Alzheimer’s disease is a specific disease and a common cause of dementia.

Can a blood test diagnose Alzheimer’s disease?

Blood biomarkers can support diagnosis in appropriate clinical contexts, but interpretation depends on symptoms, age, and the broader clinical picture.

Do biomarkers predict exactly when symptoms will start?

Not exactly. Some research models can estimate symptom onset windows, but prediction uncertainty is still too large for exact forecasting in individuals.

Further reading