How Is Dementia Diagnosed? A Geriatric Doctor Explains

how is dementia diagnosed

What it takes to get a dementia diagnosis

So many families ask “how is dementia diagnosed?”

If you’re concerned that your older adult might have Alzheimer’s disease or dementia, it’s important to know how to get an accurate diagnosis.

This is essential because dementia-like symptoms could be caused by other reversible health conditions. An accurate diagnosis is needed for proper treatment.

Knowing what a doctor should evaluate helps you protect your older adult in case their doctor jumps to a diagnosis without going through the full exam and tests.

Dr. Leslie Kernisan, an experienced geriatric doctor , wrote an article to explain how doctors typically evaluate and diagnose problems with memory, thinking, or judgment.

She describes the basic diagnostic tests, what types of information are needed, and how long the process takes.

Here, we summarize key points from her article:

  • 5 key symptoms of dementia
  • 5 steps doctors take to diagnose dementia
  • Why dementia can’t be diagnosed in a single doctor’s appointment
  • What to do if you feel the doctor may be jumping to conclusions
  • How to prepare if your older adult needs to be evaluated for Alzheimer’s disease or dementia.

5 key symptoms of dementia

Dr. Kernisan describes the 5 issues that people with dementia typically experience:

  • Difficulty with one or more types of mental function, like learning, memory, language, judgement
  • Problems that are a change compared to the person’s usual abilities
  • Problems that make it difficult for them to manage everyday life responsibilities, like work or family
  • Problems that aren’t caused by another mental disorder, like depression


5 steps doctors take to diagnose dementia

Doctors typically go through 5 areas of evaluation to figure out whether or not someone has dementia. The doctor needs to check each area and document what they find.

1. Difficulty with mental functions
This is usually evaluated with a combination of an office-based cognitive test and finding out about real-world problems by talking with their patient and people close to them.

2. Decline from previous level of ability
This can be more difficult for a doctor to determine, so they need to talk with people who know the patient well to understand their previous abilities versus what they can do today.

For example, if a former accountant can no longer do basic math, that’s a decline from their previous ability.

3. Impairment of daily life function
This can also be tough for doctors to evaluate on their own.

So, the doctor will ask people close to their patient about what types of help the person is getting in their daily life and what problems family members have noticed.

4. Reversible causes of cognitive impairment
Certain conditions can cause temporary dementia-like symptoms.

Delirium can seem like Alzheimer’s or dementia and is usually caused by illness, infections, or a hospitalization and can last from weeks to months.

Other medical problems that interfere with thinking skills include medication side effects, thyroid problems, electrolyte imbalances, B12 deficiency, substance abuse, and other treatable health conditions.

5. Other mental disorders
Depression is a common mental health issue for seniors and can sometimes be confused with dementia symptoms.

And sometimes, they could have depression and dementia at the same time.

It’s also important to consider the person’s mental health history. Paranoia or delusions could be related to mental health conditions like schizophrenia.


Dementia cannot be diagnosed in a single visit

The 5 areas a doctor must evaluate to give a proper dementia diagnosis are complex and require a lot of information gathering and lab tests.

So it’s highly unlikely that any doctor could make an accurate diagnosis in one office visit.


What to do if a doctor jumps to a diagnosis in a single visit

Unfortunately, some doctors do jump quickly to a dementia diagnosis in only one visit. Even worse, they don’t properly document what led to their decision.

If this happens, you may want to seek a second opinion from a doctor who is willing and able to do more thorough evaluation and testing.

Yes, there is a chance that your older adults symptoms could mean that they have dementia.

But what if their dementia-like symptoms are caused by other reversible health conditions?

That’s why an accurate diagnosis is essential for proper treatment.


How to prepare for a dementia evaluation

If you’re concerned that your older adult could have Alzheimer’s or dementia, Dr. Kernisan provides a free tip sheet of the types of information you should gather to help the doctor make a better and faster diagnosis.


Next Step  Dr. Kernisan explains how to get an accurate Alzheimer’s or dementia diagnosis and shares tips on how to get a better and faster diagnosis


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By DailyCaring Editorial Team


This article wasn’t sponsored and doesn’t contain affiliate links. For more information, see How We Make Money.


  • Reply September 17, 2021


    My husband was diagnosed 6 months. I’m his sole provider. I started teaching online because of COVID so that has allowed me to stay with him. I love my husband and I’m willing to be there for him and care for him in any way he needs. It’s hard though…

  • Reply June 21, 2021

    Bobbie Sena

    How horrible! 1 1 How frightening! 1 1 I saw so many precious friends go through ths sort of treatment! ! !They are all in heaven now. I am so very very thankful that thus far my darling son and daughter in law assure me that I am as mentally competent as ever.A year ago a doctor tested me for dementia just because I had tripped and fallen and came to her for a wound treatment. I was told that I “aced’ the exam.At 87, i am enjoying life a lot. However, I dread the possibility of losing my precious freedom.

    • Reply June 21, 2021


      It’s wonderful to hear that you’re in good cognitive health!

  • Reply February 28, 2021


    This is exactly what my husband & I going through. Last summer i took him to a memory testing doctor, had been seen there once before back 4 years ago. My husband has multiple health issues, CHF, diabetes uncontrolled, chronic depression.that dr’s diagnosis is vascular dementia with behavioral issues. He is unable to have MRI to rule it out because of uncapatible pacemaker/defibulator.
    When requesting a second opinion we were denied & sent to a neurologist & a psychiatrist. At the time of Diagnosis they were basing it on previous hospital stays & determinations of a stroke & heart attack. Cardiologist had stated that these were
    incorrect diagnosis. Should i take him to be retested some where else?

    • Reply February 28, 2021


      It can definitely be a long and challenging process to get a proper dementia diagnosis. If you’re questioning the current diagnosis, you may want to keep working on getting a second opinion from a different doctor or specialist. You may also want to speak further with the cardiologist to understand why they’re saying that the diagnosis is incorrect.

      You might also want to seek out a geriatric doctor, who specializes in senior patients, or a doctor who specializes in people with dementia.

      We’ve got more info on geriatric doctors here – What Does a Geriatric Doctor Do? How Seniors Can Benefit From a Specialist

  • Reply May 20, 2019

    Robert Kaznica

    That’s all well and good but what if the patient flat out refuses to see a doctor. My mother all her life has avoided and distrust doctors. I can’t even get her into a office let alone agree to any testing

    • Reply July 28, 2019


      That can definitely be a tough situation. Sometimes it’s necessary to find creative (or even sneaky) approaches to get someone to do what’s necessary to keep them as healthy as possible.

      To get her to the doctor, you may need to trick her into going. Even if she may be angry about it later, the more important thing is to make sure the doctor can evaluate her health.

      One idea is to secretly make a doctor’s appointment and not mention the appointment at all. It’s a good idea to speak with the doctor’s office ahead of time to explain the situation and ask them to help out as much as possible.

      Then on the appointment day, don’t tell her that she’s going to the doctor and say that you’re going out to lunch, to have coffee, meet a friend, go grocery shopping — whatever it is that she enjoys or that she’ll go along with.

      Then, head for the doctor’s office and when she asks why you’re going there, say that you just need to make a quick stop first before going to do the activity. You could even say that you need to pick something up from “your” doctor.

      Hopefully once she’s in the doctor’s office, she’ll be able to follow the routine of the office visit and the nurses and staff will help.

      Hopefully this will help you brainstorm ideas that will work best for your situation.

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