Forgetting a name, losing your keys, or needing a reminder once in a while doesn’t automatically mean dementia.
But when memory, thinking, language, or decision-making problems start affecting everyday life, it’s worth getting checked.
Dementia isn’t one disease, and there isn’t one test that can diagnose it. Doctors usually combine information from your medical history, symptoms, cognitive tests, physical and neurological examinations, blood tests, and brain scans. In some cases, they may also use Alzheimer’s blood biomarkers, PET scans, or a spinal fluid test [1].
Alzheimer’s disease is the most common cause of dementia and accounts for an estimated 60% to 80% of dementia cases. Other causes include vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia [2].
The goal of diagnosis isn’t simply to confirm dementia. Doctors also need to find out what’s causing the symptoms.
Occasionally the cause can be treated.
That’s why getting checked early matters.
Why Early Dementia Diagnosis Matters: 6 Reasons
1. Some Memory Loss is Reversible
Not every memory problem means dementia.
Vitamin deficiencies, thyroid problems, depression, sleep problems, medication side effects, and some infections can cause symptoms that look like dementia. Hearing and vision problems can also make communication and memory difficulties worse [2, 3].
Some of these problems can improve when the underlying cause is treated.
For example, a doctor may find that a person has a vitamin B12 deficiency or a thyroid disorder and treat it instead of assuming the person has Alzheimer’s disease.
Some medicines can also affect memory, concentration, or alertness. That’s why your doctor will usually review every medicine and supplement you’re taking.
Sudden confusion is different from the gradual memory changes usually seen in dementia. In older adults, infections and other medical problems can cause delirium, which needs prompt medical attention.
The first question should be, “What’s causing this?”
Not: “Is this definitely dementia?”
2. Newer Treatments Work Only in Early Stages
Early diagnosis is important because it can help identify treatment options at an earlier stage of Alzheimer’s disease.
Some newer disease-modifying treatments for Alzheimer’s disease target beta-amyloid, a protein associated with the disease. Clinical trials have shown that these medicines can slow cognitive and functional decline in some people with early Alzheimer’s disease.
They don’t cure Alzheimer’s disease, and they aren’t suitable for everyone.
They can also cause side effects, including amyloid-related imaging abnormalities, which may involve brain swelling or bleeding.
An accurate diagnosis is therefore important before a specialist considers whether a person could benefit from these treatments.
Alzheimer’s Society has also highlighted early diagnosis as an important step in identifying people who may be eligible for disease-modifying treatments as they become available. [3]
3. Symptom Medicines Work Better Started Early
Some medicines can help manage symptoms of Alzheimer’s disease.
Doctors may prescribe medicines to help manage memory and thinking problems. Other medicines may also be used in moderate or severe Alzheimer’s disease.
These medicines don’t cure dementia or stop the underlying disease.
They may help some people with memory, thinking, or daily functioning for a period of time.
Starting treatment after a proper assessment gives your doctor a chance to see whether it’s helping and monitor side effects.
4. Time For Legal and Financial Planning
A diagnosis gives families something that uncertainty doesn’t: Time.
A person in the early stages may still be able to make decisions about finances, property, healthcare, and future care.
An Alzheimer’s Society survey of 1,019 people affected by dementia found that 91% saw at least one benefit from receiving a diagnosis. The survey also found that 1 in 4 people had waited two years after experiencing symptoms before seeking a diagnosis. [4]
Another Alzheimer’s Society survey found that 3 out of 5 people with dementia wished they had received their diagnosis sooner. [5]
An early diagnosis can give families time to discuss legal documents, financial arrangements, healthcare preferences and future care.
5. Safety: Driving, Money, Medicines
Memory problems can affect everyday safety.
A person may forget whether they’ve taken a medicine, pay the same bill twice, leave an appliance switched on, or become lost on a familiar route.
Problems with planning, judgement, and problem-solving can also affect driving and financial decisions.
An early diagnosis helps families identify these risks and decide where support is needed.
It doesn’t mean that every activity has to stop immediately.
Instead, families and doctors can look at what remains safe and make changes when needed.
6. Access to Clinical Trials
An early diagnosis may also give a person the opportunity to take part in clinical research.
Clinical trials often have strict requirements based on the type and stage of dementia. Some may also require evidence of Alzheimer’s-related changes such as amyloid or tau protein.
The Alzheimer’s Association lists access to clinical trials and research studies among the potential benefits of an early diagnosis. [2]
Research is also moving toward identifying Alzheimer’s-related brain changes before symptoms become severe.
According to Alzheimer’s Society research, it supported the finding that some brain changes associated with dementia may begin up to 15 years before symptoms become noticeable. [3]
That doesn’t mean everyone with these early biological changes will definitely develop dementia. It shows why researchers are studying the long period between changes in the brain and noticeable symptoms.
How Is Dementia Diagnosed? Step by Step
1. History and Family Interview
Diagnosis usually begins with a detailed conversation.
Your doctor may ask:
- When did the symptoms start?
- Are they getting worse?
- What changes have you noticed?
- Has behavior or personality changed?
- Are medicines being taken correctly?
- How well are daily activities being managed?
- Are there sleep problems?
- Has there been depression or anxiety?
- Is there a family history of dementia?
- Have there been previous illnesses or head injuries?
A family member or close friend can be very helpful.
People with memory problems aren’t always aware of every change themselves. Someone close to them may notice repeated questions, missed appointments, unusual spending, or difficulty with familiar tasks [1].
The doctor may also ask about everyday activities such as cooking, shopping, paying bills, managing medicines, and travelling independently.
This helps determine whether the symptoms are affecting the person’s ability to function.
2. Cognitive Screening Tests
The next step may involve a short test of memory and thinking.
You may be asked to remember words, draw a clock, name objects, follow instructions, answer questions about the date or location, or solve simple problems [1].
Two commonly used screening tools are the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA).
Both use a 30-point scale. The MMSE checks areas such as memory, concentration, and orientation. The MoCA also assesses attention, language, executive skills, memory, and visuospatial abilities [1].
WebMD notes that a score of 23 or below on the MMSE or 22 or below on the MoCA may lead to further testing, but these cut-offs aren’t a diagnosis on their own [1].
Your score can also be affected by education, language, hearing, vision, and other factors.
That’s why doctors look at the test result alongside your symptoms and medical history.
If more information is needed, you may be referred for neuropsychological testing. This involves more detailed tests of different thinking abilities.
3. Blood Tests to Rule Out Other Causes
Blood tests are an important part of the dementia workup.
Depending on the person’s symptoms, doctors may check:
- Vitamin B12
- Thyroid function
- Blood sugar
- Blood counts
- Kidney function
- Liver function
- Other tests based on medical history
These tests can help identify health problems that may cause or worsen cognitive symptoms [1].
For example, vitamin deficiencies and thyroid disorders can affect thinking and memory.
Some medicines can also cause confusion or drowsiness, so a medication review is often part of the assessment.
But routine blood tests usually can’t tell you that someone has Alzheimer’s disease.
That’s different from specialized Alzheimer’s blood biomarker tests.
4. Brain Imaging
Doctors may recommend a CT scan or MRI of the brain.
A CT scan uses X-rays to create images of the brain. An MRI uses magnets and radio waves to produce more detailed images.
Both can help doctors look for other causes of cognitive problems, including stroke, bleeding, or a brain tumor [1].
A PET scan may be used in some cases.
Certain PET scans can show amyloid plaques in the brain, which can provide evidence of Alzheimer’s disease.
Not everyone with memory problems needs a PET scan. The decision depends on the symptoms and whether the result would help clarify the diagnosis or treatment.
5. Alzheimer’s Blood Biomarker Tests
Blood-based tests for Alzheimer’s disease are one of the fastest-moving areas of dementia research.
Some tests measure beta-amyloid or phosphorylated tau, including p-tau217.
These biomarkers can provide information about biological changes associated with Alzheimer’s disease [1].
Research has produced promising results.
In July 2019, research from the United States tested an Alzheimer’s blood test in 158 people and reported 94% accuracy in identifying people who would go on to develop Alzheimer’s disease [3].
In February 2023, the Alzheimer’s Society reported research from the University of Pittsburgh involving a blood test that detected a specific form of tau from the brain. The researchers reported accuracy ranging from 86% to 99% for detecting Alzheimer’s disease [3].
Researchers at the University of Washington also developed a blood test that detected a toxic form of amyloid and reported 98% accuracy [3].
These numbers come from individual research studies. They don’t mean every Alzheimer’s blood test is 98% or 99% accurate.
Test performance can vary based on the biomarker, test method, study population, and clinical setting.
That’s why these tests should be interpreted by trained healthcare professionals and used as part of a wider assessment.
Routine blood tests and Alzheimer’s blood biomarker tests should not be confused.
A routine blood test may help identify vitamin B12 deficiency or thyroid disease. A biomarker test looks for biological evidence associated with Alzheimer’s disease.
6. Spinal Fluid Test
A spinal fluid test, also called a lumbar puncture, can provide another way to look for Alzheimer’s-related proteins.
During the procedure, a doctor uses a thin needle to collect a small amount of cerebrospinal fluid from the lower back.
The sample can be tested for proteins such as amyloid and tau.
This test isn’t needed for everyone.
A specialist may recommend it when the diagnosis remains uncertain or when confirming Alzheimer’s-related changes could affect treatment decisions.
Why Dementia Can Be Difficult to Diagnose
Dementia doesn’t look the same in everyone.
Memory loss is often an early symptom of Alzheimer’s disease. But other dementias may begin with changes in behavior, language, attention, movement, or visual processing.
There can also be more than one cause at the same time.
For example, a person may have Alzheimer’s-related brain changes as well as vascular disease. This is known as mixed dementia [2].
That’s why doctors don’t rely on one test.
A scan, blood test or memory score may provide an important clue, but the final diagnosis comes from putting the different pieces together.
Which Doctor Should You See?
You don’t always need to start with a neurologist.
A primary-care doctor or physician can begin the evaluation. They can review your symptoms, medicines and medical history, perform an initial cognitive assessment and order basic tests.
Depending on the results, you may be referred to a:
- Neurologist
- Geriatrician
- Psychiatrist
- Neuropsychologist
- Memory clinic
WebMD lists neurologists, psychiatrists, psychologists, neuropsychologists and geriatricians among specialists who may be involved in dementia evaluation[1].
If symptoms are unusual, progressing quickly or difficult to explain, a specialist assessment may be needed.
Sudden confusion is different.
If someone suddenly becomes confused, develops weakness, has trouble speaking, loses consciousness, or has another sudden neurological change, seek urgent medical care.
What Families Can Do Before the Appointment
Don’t wait until the appointment to try to remember everything.
Write down when the symptoms started and give specific examples.
For example:
- Repeating the same question
- Forgetting recent conversations
- Getting lost in familiar places
- Missing bills or paying them twice
- Forgetting medicines
- Leaving appliances switched on
- Struggling with familiar recipes
- Having trouble finding common words
- Becoming unusually confused
- Showing changes in mood or behaviour
Bring a complete list of prescription medicines, over-the-counter medicines, vitamins and supplements.
Also note previous illnesses, hospitalisations, head injuries, sleep problems and changes in mood.
If possible, take someone who knows the person well to the appointment.
WebMD recommends preparing a list of symptoms, recent life changes or major stressors, medicines and supplements, along with questions for the doctor[1].
What Families Can Do After a Diagnosis
A diagnosis gives your family a starting point.
Ask the doctor:
- What type of dementia is it?
- What stage is it?
- What caused it?
- What treatments are available?
- What side effects should we watch for?
- What safety changes should we make?
- Should we see a specialist?
- Are there clinical trials we should know about?
Keep a current list of medicines and appointments.
Review driving, cooking, handling money, and taking medicines as symptoms change.
Lifestyle habits can also support overall health. Regular physical activity, good sleep, a balanced diet, social interaction, and management of conditions such as high blood pressure and diabetes are useful parts of healthy aging.
You can read more about 7 lifestyle changes that may help lower the risk of Alzheimer’s disease.
and normal forgetfulness or early dementia? 10 Signs Families Notice First
Walking is another simple way to stay active. A regular walking routine can be easier to maintain than a complicated exercise plan. Read more about the benefits of morning walking.
Families should also discuss healthcare preferences, finances, and legal arrangements while the person can still take part in those decisions.
Dementia Diagnosis: A Simple Family Checklist
Before the appointment:
☐ Write down when symptoms started.
☐ Note specific memory or behavior changes
☐ List all medicines and supplements.
☐ Note sleep and mood changes
☐ Record recent infections, falls, or hospital visits.
☐ Note any family history of dementia.
☐ Take someone who knows the person well.
☐ Write down questions for the doctor.
After the appointment:
☐ Ask what type of dementia is suspected.
☐ Ask whether more tests are needed.
☐ Discuss treatment options
☐ Review medicine safety
☐ Discuss driving and other safety concerns
☐ Start legal and financial planning when appropriate.
☐ Ask about support services
☐ Ask whether clinical trials may be suitable.
Disclaimer: This is a sponsored article powered by Sun Pharmaceutical Industries Limited. The information provided in this article is in the form of text, tips, and suggestions, which comprise general advice for consumers. Tata 1mg does not endorse any brands and is not responsible for their efficacy.
Frequently Asked Questions
1. Is there a blood test for Alzheimer’s?
Yes. Some blood tests detect Alzheimer’s-related proteins such as amyloid and phosphorylated tau. They should be interpreted alongside symptoms and other assessments [1].
2. Is dementia treatable?
Some causes of memory problems are treatable. Dementia itself has no cure, but medicines may help symptoms, and some newer treatments can slow progression in certain people with early Alzheimer’s disease.
3. Is there a cure for Alzheimer’s yet?
No. There is currently no cure for Alzheimer’s disease. Some newer medicines can slow progression in selected people with early disease.
4. Are online memory tests reliable?
They can raise a concern, but they can’t diagnose dementia. A proper medical assessment is needed to find the cause of memory problems.
The article is written by Mantasha, Sr. Executive, Clinical Health & Content, and reviewed by Monalisa Deka, Deputy Manager, Clinical Health & Content, Medical Affairs.)
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References
1. WebMD. How Is Dementia Diagnosed? Medically reviewed February 19, 2025. Available at: https://www.webmd.com/alzheimers/diagnose-dementia
2. Alzheimer’s Association. What Is Dementia? Available at: https://www.alz.org/alzheimers-dementia/what-is-dementia
3. Alzheimer’s Society. Why spotting the early signs of dementia is so important. February 16, 2023. Available at: https://www.alzheimers.org.uk/blog/why-spotting-early-signs-dementia-important
4. Alzheimer’s Society. 91% of people affected by dementia see clear benefits to getting a diagnosis. Survey of 1,019 people affected by dementia. Available at: https://www.alzheimers.org.uk/news/2022-05-16/91-people-affected-dementia-see-clear-benefits-getting-diagnosis
5. Alzheimer’s Society. Benefits of getting a dementia diagnosis. Available at: https://www.alzheimers.org.uk/about-dementia/dementia-diagnosis/benefits-of-getting-dementia-diagnosis