# Alzheimer's Tests: How Doctors Diagnose It in 2024

> From cognitive screens to PET scans and new blood biomarkers, here's how doctors test for Alzheimer's and what families should expect.

## Meta
- URL: https://aegisv2.epekdigital.com/resources/blog/suspect-alzheimers-tips-and-tests-for-detection
- Focus keyword: alzheimer's tests
- Category: memory-care-dementia
- Tags: alzheimers, depression-anxiety, nutrition, brain-health, when-its-time, legal-planning, for-caregivers
- Published: 2014-05-13

There is no single "Alzheimer's test." Diagnosis comes from a battery of evaluations - a physical exam, medical and family history, cognitive screens like the Mini-Cog or MMSE, brain imaging (MRI or PET), bloodwork, and increasingly, biomarker tests that detect amyloid and tau proteins. A specialist combines these results to rule out other causes and confirm Alzheimer's, often before symptoms become severe.

Catching the disease early matters. An estimated 6.9 million Americans age 65 and older are living with Alzheimer's, and only about 4 in 10 with symptoms ever get a formal diagnosis ([Alzheimer's Association](https://www.alz.org/alzheimers-dementia/facts-figures), 2024). If you're noticing changes in a parent, start by reviewing the [Early Signs of Dementia: 10 Symptoms Families Notice First](/early-signs-of-dementia-10-symptoms-families-notice-first/), then book a workup with their primary care doctor.

## When should you ask the doctor about an Alzheimer's test?

Forgetting a name is normal aging. Forgetting the relationship is not. Schedule a cognitive evaluation if your parent shows any of these patterns for more than a few weeks:

- Repeating the same question within minutes

- Getting lost on familiar routes

- Struggling with bills, recipes, or appliances they used for decades

- Personality shifts, withdrawal, or new suspicion of family members

- Leaving the stove on or medications untaken

For example, an 82-year-old who has cooked the same Thanksgiving stuffing for 40 years and now cannot follow the recipe is showing a meaningful change - not a quirk. Before assuming the worst, read about [8 Conditions That Mimic Dementia (And Are Often Treatable)](/resources/blog/before-you-assume-its-dementia-consider-these-conditions-that-can-cause-dementia-like-symptoms/), since thyroid disease, B12 deficiency, depression, and medication interactions can produce identical symptoms.

## What does a full Alzheimer's workup include?

The Mayo Clinic and the Alzheimer's Association describe a standard workup with several layers ([Alzheimer's Association](https://www.alz.org/alzheimers-dementia/diagnosis/medical_tests), 2024). Each test answers a different question.

TestWhat it measuresTypical setting

Physical exam and labsVitals, blood, urine, thyroid, B12, liver, kidneyPrimary care
Medical and family historyMedications, chronic disease, relatives with dementiaPrimary care
Mini-Cog or MMSEShort cognitive screen, 3 to 10 minutesPrimary care
Neuropsychological testingDetailed memory, language, executive functionNeuropsychologist, 2 to 4 hours
MRI or CT scanRules out stroke, tumor, hydrocephalusImaging center
Amyloid PET scanDetects amyloid plaques in the brainSpecialty center
Blood biomarker (p-tau 217)Detects Alzheimer's-related tau proteinSpecialist, available 2024
CSF (spinal fluid) testMeasures amyloid and tau directlyNeurologist

## How accurate are the newer blood tests?

Until recently, confirming Alzheimer's biology required a PET scan or a spinal tap. That changed in 2024. A blood test measuring phosphorylated tau 217 (p-tau 217) identified Alzheimer's pathology with roughly 90% accuracy in a large clinical study, performing comparably to specialist evaluation (National Institute on Aging, 2024). The test is now available through some specialty clinics, though Medicare coverage is still evolving.

As geriatrician Louise Aronson, MD, author of *Elderhood*, has emphasized, earlier and clearer diagnosis lets families plan while the person with dementia can still participate in decisions about their care, finances, and home.

## What do the cognitive screening tests actually look like?

Two short tools dominate primary care:

Mini-Cog
A 3-minute screen. The patient remembers three words, draws a clock showing a specific time, then recalls the three words. Scoring is simple and free for clinicians to use.
MMSE (Mini-Mental State Exam)
A 30-point questionnaire covering orientation, recall, attention, language, and visual construction. A score below 24 suggests cognitive impairment, though education and language affect results.
MoCA (Montreal Cognitive Assessment)
A 30-point test more sensitive to mild cognitive impairment than the MMSE, useful when symptoms are subtle.

Consider a 78-year-old retired engineer who scores 27 on the MMSE - apparently "normal" - but cannot complete the MoCA's trail-making and abstraction tasks. That gap is a flag for early Alzheimer's that a quick screen alone would miss.

## How should you prepare for the appointment?

- **List every medication and supplement.** Include doses. Anticholinergics, benzodiazepines, and even some over-the-counter sleep aids can mimic dementia (CDC Healthy Brain Initiative, 2024).

- **Write a timeline of changes.** Note when memory lapses started and what triggers them.

- **Bring a family informant.** Doctors rely heavily on what a spouse or adult child has observed.

- **Request bloodwork in advance.** Thyroid panel, B12, CBC, comprehensive metabolic panel, and a vitamin D level can reveal reversible causes.

- **Ask about referral to a memory clinic.** If the primary care screen is abnormal, a neurologist or geriatric psychiatrist can order imaging and biomarker testing.

- **Discuss legal planning early.** Powers of attorney signed after diagnosis are far harder to defend ([National Academy of Elder Law Attorneys](https://www.naela.org/), 2024).

## What if the test results point to Alzheimer's?

A diagnosis is not a verdict on next week, it is a roadmap for the next decade. Two new disease-modifying drugs, lecanemab and donanemab, can slow early Alzheimer's by clearing amyloid from the brain ([U.S. Food and Drug Administration](https://www.fda.gov/news-events/press-announcements/fda-converts-novel-alzheimers-disease-treatment-traditional-approval), 2023). Eligibility is narrow and the drugs carry real risks, so a specialist consultation is essential.

Lifestyle still matters after diagnosis. Aerobic exercise, the MIND diet, hearing aids, sleep treatment, and social engagement are all tied to slower decline; see our companion guide to [8 Science-Backed Ways to Reduce Your Alzheimer's Risk](/resources/blog/8-ways-combat-alzheimers-disease/). Families should also rule out vascular contributors by reading [What Is Vascular Dementia](/resources/blog/what-is-vascular-dementia-understanding-the-second-most-common-type-of-dementia/), and reassess alcohol use, which is covered in [Does Alcohol Cause Dementia?](/resources/blog/does-alcohol-cause-dementia/)

## Frequently asked questions

### Can a primary care doctor diagnose Alzheimer's, or do you need a specialist?

A primary care physician can begin the workup with labs, a Mini-Cog, and a medication review. Confirming Alzheimer's specifically - distinguishing it from vascular dementia, Lewy body dementia, or frontotemporal disease - usually requires a neurologist, geriatrician, or memory clinic, especially when imaging or biomarker testing is needed.

### Does Medicare cover Alzheimer's testing?

Medicare covers an annual cognitive assessment as part of the Annual Wellness Visit, plus medically necessary bloodwork, MRI, and CT scans ([Medicare.gov](https://www.medicare.gov/coverage/cognitive-assessment-care-plan-services), 2024). Amyloid PET scans gained broader coverage in 2023, and coverage of new blood biomarker tests is still being finalized.

### How long does it take to get an Alzheimer's diagnosis?

From first appointment to a confirmed diagnosis often takes 2 to 6 months, depending on specialist wait times and which imaging is ordered. A simple cognitive screen happens the same day, but PET scans and neuropsychological testing usually require separate referrals.

### Should adult children get genetic testing for Alzheimer's?

For most families, no. The APOE-e4 gene raises risk but does not guarantee disease, and a positive result can cause anxiety without changing treatment. Genetic testing is generally reserved for families with early-onset Alzheimer's (before age 65) across multiple generations, and only after counseling.

### Is mild cognitive impairment the same as Alzheimer's?

No. Mild cognitive impairment (MCI) means measurable changes in thinking that do not yet disrupt daily life. Roughly 10 to 15% of people with MCI progress to dementia each year, but some remain stable or even improve when the cause is reversible ([National Institute on Aging](https://www.nia.nih.gov/health/memory-loss-and-forgetfulness/what-mild-cognitive-impairment), 2024).

### What questions should I ask the doctor after testing?

Ask which specific diagnosis was made, how confident the physician is, whether reversible causes were ruled out, what the next 12 months may look like, and whether your parent qualifies for disease-modifying therapy or a clinical trial. Also ask for written instructions you can review at home.

If testing confirms Alzheimer's, the next decision is how to support daily life safely. Aegis Living's memory care teams help families think through that transition. [Find an Aegis Living community near you](/find-a-location/) or [contact us](/contact/) to talk with a care advisor.