How dementia testing works

Dementia testing is not a single test. Instead, your doctor will use a combination of conversations, memory checks, and sometimes brain imaging to understand what is happening. The goal is to figure out whether memory loss or confusion is normal aging, a treatable condition like a vitamin deficiency, or dementia—and if it is dementia, what type.

Most testing happens in your doctor's office or a memory clinic. Your primary care doctor can start the process, or you can ask for a referral to a neurologist (a doctor who specializes in the brain and nervous system) or a geriatrician (a doctor who specializes in older adults). Some hospitals have dedicated memory clinics that bring together neurologists, neuropsychologists, and other specialists.

The whole process usually takes several weeks from your first appointment to a diagnosis, because some tests take time to schedule and results need to be reviewed carefully.

Key Takeaways

  • Your primary care doctor can order basic memory tests and bloodwork, or refer you to a neurologist or memory clinic for more detailed evaluation.
  • Doctors use memory tests, thinking tests, blood tests, and sometimes brain imaging (MRI or CT scan) to diagnose dementia.
  • Bring a family member or close friend to your appointment if you can, because they can describe changes they have noticed that you might not remember.
  • Testing can take several weeks from start to diagnosis, and some results may be reviewed by multiple doctors before you get a final answer.
  • If your doctor finds treatable causes of memory loss—like low vitamin B12, thyroid problems, or depression—treating those may improve your thinking and memory.

Starting with your primary care doctor

Your first step is usually a visit to the doctor you see regularly. Tell them about the memory or thinking problems you or a family member have noticed. Be specific: Is it forgetting recent conversations? Getting lost in familiar places? Trouble with everyday tasks like cooking or paying bills? The more detail you give, the better your doctor can assess what is happening.

Your doctor will ask about when the problems started, how fast they are getting worse, and whether anything else has changed—sleep, mood, medications, or general health. They will also ask about your family history, because some types of dementia run in families.

At this visit, your doctor will likely do a brief memory test in the office. Common ones are the Montreal Cognitive Assessment (MoCA) or the Mini-Cog test. These take 10 to 15 minutes and ask you to remember words, draw a clock, or answer questions about the date and place. These are screening tests, not a diagnosis—they help your doctor decide whether further testing is needed.

Your doctor will also order blood tests to rule out treatable causes: vitamin B12 deficiency, thyroid problems, depression, anemia, or infections. These are important because treating them can sometimes improve memory and thinking.

When you need a specialist

If your primary care doctor's tests suggest dementia, or if the cause is unclear, you will be referred to a specialist. A neurologist is trained to diagnose dementia and can order advanced tests. A geriatrician specializes in older adults and takes a broader view of your overall health. Some areas have memory clinics that combine both approaches.

A specialist appointment is longer than a regular doctor visit—often 60 to 90 minutes. The doctor will go over your medical history in detail, ask more questions about memory and thinking changes, and do more thorough cognitive testing. They may ask you to do tasks like naming objects, solving simple math problems, or copying drawings.

The specialist may also ask to speak with a family member or close friend separately, because people with early dementia often do not notice or remember their own changes. A spouse or adult child can describe what they have actually seen—repeated questions, getting lost, trouble managing money—which is crucial information.

Brain imaging and other tests

If dementia seems likely, your doctor will order brain imaging to look for physical changes. An MRI (magnetic resonance imaging) or CT scan (computed tomography) takes pictures of your brain and can show shrinkage, stroke, or other damage. These scans are painless but can be loud (MRI) or involve a small amount of radiation (CT). The scan itself takes 20 to 45 minutes.

Some specialists also order a PET scan (positron emission tomography), which shows how the brain is using energy and can reveal patterns typical of Alzheimer's disease or other types of dementia. PET scans are less common than MRI or CT and may not be covered by insurance, so ask your doctor about cost before the test is scheduled.

In some cases, your doctor may order additional blood tests that look for specific proteins in your blood—like amyloid or tau—that are associated with Alzheimer's disease. These are newer tests and not yet standard everywhere, but they are becoming more common.

Occasionally, if the diagnosis is still unclear after imaging and cognitive testing, your doctor may refer you for neuropsychological testing. This is a detailed evaluation by a psychologist who specializes in brain function. It takes several hours and involves memory tests, attention tests, language tests, and reasoning tests. It gives a very detailed picture of which thinking skills are affected and which are still normal.

What happens after testing

Once all tests are done, your doctor will review the results and meet with you to discuss what they found. If dementia is diagnosed, your doctor will tell you the type—Alzheimer's disease, vascular dementia, Lewy body dementia, frontotemporal dementia, or another type. The type matters because different types progress differently and respond to different treatments.

Your doctor will also talk about what to expect, what treatments or lifestyle changes might help, and what support is available. This is a good time to ask questions and to discuss your wishes for future care—whether you want to stay at home as long as possible, what kind of help you might need, and whether you want to involve family members in planning.

If the testing found a treatable cause—like a vitamin deficiency, thyroid problem, or depression—your doctor will start treatment for that. Sometimes treating these conditions improves memory and thinking significantly.

Your doctor may also refer you to other services: a social worker who can help you plan for future care, a support group for people with dementia or their caregivers, or a memory care program that offers ongoing monitoring and treatment adjustments.

Preparing for your appointment

Before your first appointment, write down the memory or thinking problems you have noticed, when they started, and how they have changed. Write down all medications you take, including over-the-counter drugs and supplements, because some can affect thinking. Bring a list of any medical conditions you have and any surgeries you have had.

Bring a family member or close friend if you can. They can help you remember details, take notes, and ask questions. They can also tell your doctor about changes they have observed.

Bring your insurance card and a photo ID. Ask ahead whether the office needs any paperwork filled out before your visit. If you have had previous medical records or test results from another doctor, bring those too—they help your new doctor see how things have changed over time.

Write down your questions before the appointment so you do not forget to ask them. It is common to feel anxious or overwhelmed during a dementia evaluation, and having questions written down helps you get the information you need.

Frequently Asked Questions

Can my primary care doctor diagnose dementia, or do I have to see a specialist?

Your primary care doctor can do initial testing and refer you to a specialist if needed. Some primary care doctors feel confident diagnosing straightforward cases of Alzheimer's disease, especially if imaging and cognitive tests are clear. However, if the diagnosis is unclear, if symptoms are unusual, or if you are younger than 65, a specialist evaluation is usually recommended.

How long does it take to get a diagnosis?

From your first appointment to a final diagnosis usually takes two to six weeks, depending on how quickly tests can be scheduled and results reviewed. If you need a specialist referral, add another two to four weeks for that appointment. Some tests like neuropsychological testing take longer to schedule.

Will the tests hurt?

Memory and thinking tests are not painful—they are just questions and tasks. Blood tests involve a needle stick that lasts a few seconds. Brain imaging (MRI or CT) is painless, though MRI is loud and can feel claustrophobic. Tell your doctor if you are anxious about any test so they can help you prepare.

What if the tests do not show dementia but I still have memory problems?

Memory problems can come from many causes: depression, sleep problems, stress, medication side effects, or normal aging. If testing rules out dementia, your doctor will work with you to find the actual cause and treat it. Sometimes a follow-up appointment in six months or a year helps track whether thinking is staying stable or changing.

Can dementia testing be done at home or through telehealth?

Some initial screening can be done by video visit with your primary care doctor. However, brain imaging and detailed specialist evaluation usually require an in-person visit. Ask your doctor whether any part of your evaluation can be done remotely.