Dementia Symptoms and Diagnosis

If you are reading this page, someone you care about may be showing changes in memory, language, behaviour, or daily function — and you are trying to understand what is happening. This hub is a routing page for the parts of HelpDementia.com that cover dementia symptoms, the staging system, the cognitive tests doctors use, and what brain-imaging findings actually mean. It is not a substitute for a clinical evaluation. If a change worries you, the most useful next step is almost always a conversation with the person’s primary care doctor or a neurologist.

Dementia vs Alzheimer’s What’s the difference?

DEMENTIA The general term

Dementia is a general term for a decline in thinking, remembering and reasoning that is severe enough to interfere with daily life. It is not one disease.

It affects:

• 1Memory
• 2Thinking and reasoning
• 3Language and communication
• 4Everyday activities, such as managing money, taking medications or getting dressed

ALZHEIMER’S DISEASE A specific condition

Alzheimer’s disease is a specific brain disease and the most common cause of dementia.

• It is a particular diagnosis, not a general term.
• It causes dementia, but not all dementia is caused by Alzheimer’s.
• Alzheimer’s develops gradually. In its early stages it may cause only mild changes, and it leads to dementia as it progresses.
• Having dementia does not necessarily mean a person has Alzheimer’s.

In simple terms

Think of dementia as an umbrella term. Alzheimer’s disease is one type underneath that umbrella.

The bigger picture

Dementia can be caused by different conditions that affect the brain.

DEMENTIA(the general term)

Different causes. Similar symptoms. Care that fits the type.

• Alzheimer’s diseaseThe most common cause of dementia, an estimated 60–80% of cases.
• Vascular dementiaCaused by reduced blood flow to the brain, often after strokes or damage to small blood vessels.
• Lewy body dementiaCaused by abnormal deposits of a protein called alpha-synuclein (Lewy bodies) in the brain.
• Frontotemporal dementiaAffects the frontal and temporal lobes and can change personality, behavior and language.
• Mixed and other typesMany people have more than one cause at once (mixed dementia), and there are other less common causes.

Understanding the difference can help reduce stigma, improve care and support people living with these conditions.

You are not alone.

Sources: National Institute on Aging, What Is Dementia? Symptoms, Types, and Diagnosis; Alzheimer’s Association, What Is Alzheimer’s Disease?. Read more: Alzheimer’s vs dementia: what is the difference and types of dementia explained in plain English.

Start here

• Warning signs of dementia (and how they sometimes look different in men)
• The 7 stages of Alzheimer’s and how long each stage tends to last
• A plain-English dementia progression timeline by stage

Cognitive tests, scores, and what they mean

Caregivers are often handed a number — a MoCA score, an MMSE score, a FAST scale rating — without much context about what it implies for daily care. These guides translate the scores.

• MoCA scores and dementia progression: a complete guide
• MMSE scores and dementia stages: what the numbers tell you
• FAST scale for dementia: understanding the 7-stage assessment
• Stage 6 dementia: symptoms timeline and caregiver guide

Brain MRI findings explained

If you are reading an MRI report and trying to figure out which findings are concerning and which are common in older adults, these guides decode the radiology language.

• What “microangiopathic changes” on a brain MRI mean
• What “parenchymal volume loss” means on a brain MRI
• What “encephalomalacia” means on a brain MRI
• What “small-vessel ischemic disease” means on a brain MRI

Prognosis and life expectancy

• Dementia life-expectancy chart by stage
• Vascular dementia life expectancy, compared to Alzheimer’s
• Frontotemporal dementia life expectancy by age of onset
• Dementia life expectancy by age of onset (2026 update)

Common questions

• What age does dementia usually begin?
• How likely am I to get dementia if it runs in my family?

If a doctor’s visit is your next step

Write down what you have noticed before the visit — specific examples, dates, and how often the change is happening. Doctors get a far better picture from “he forgot the route home from the grocery store twice in the last month” than from “his memory is getting worse.” Bring a list of all current medications and any over-the-counter supplements; some of those can mimic or worsen cognitive symptoms.

Other hubs you might need next

• Caregiver daily support — once you have a diagnosis
• Treatment, medications, and research explained

The articles linked from this hub are informational and not medical advice. See our Editorial Policy for how we research and review content. Last reviewed May 30, 2026.