The doctor used the word "dementia." A week later a friend asks how your mum's Alzheimer's is going. Your brother calls it "memory problems." Are you all talking about the same thing?
Mostly, yes. But not exactly, and the gap between the two words matters more than it seems. It affects which treatments are an option, what changes to expect, and how you explain things to the rest of the family.
Here's a plain-English guide to the difference, the other common types of dementia, and the questions worth asking after a diagnosis.
The Short Answer
Dementia describes a group of symptoms: changes in memory, thinking, communication and the ability to manage daily life. Alzheimer's disease is one of the diseases that causes those symptoms, and it's the most common one.
According to the World Health Organization, Alzheimer's may contribute to 60 to 70 percent of dementia cases worldwide. So every person with Alzheimer's dementia has dementia, but not everyone with dementia has Alzheimer's.
A simple way to hold it: dementia describes what is happening. The type of dementia explains why.
What Dementia Means
The WHO describes dementia as a condition that affects memory, thinking and the ability to carry out daily activities, caused by different diseases that damage the brain. It gets worse over time. It's more common after 65, but it is not an inevitable part of ageing.
Early signs listed by the WHO include:
forgetting recent events or misplacing things
getting lost, even in familiar places
losing track of time
difficulty solving problems or making decisions
trouble following conversations or finding words
difficulty with familiar tasks
Mood and behaviour can change too, sometimes before memory problems show up. The WHO lists anxiety, personality changes and withdrawal from social activities among them.
Not every memory slip is dementia. If you're not sure whether what you're seeing is normal ageing, our guide to early cognitive changes vs normal ageing is a good place to start.
What Alzheimer's Disease Is
Alzheimer's is a progressive brain disease. It involves a build-up of proteins, including beta-amyloid and tau, that damages brain cells over time. It often affects the parts of the brain involved in forming new memories first, which is why difficulty remembering recent conversations or events is a common early sign.
It's also very common. The Alzheimer's Association estimates that 7.4 million Americans aged 65 and older are living with Alzheimer's in 2026, about 1 in 9 people in that age group.
Other Common Types of Dementia
Alzheimer's gets the headlines, but several other diseases cause dementia. The WHO names these as the main ones alongside Alzheimer's.
Vascular dementia is caused by reduced blood flow to the brain, for example after a stroke or from damage to small blood vessels. Read more in What Is Vascular Dementia?
Dementia with Lewy bodies involves abnormal protein deposits inside nerve cells. Read more in What Is Lewy Body Dementia?
Frontotemporal dementia is a group of diseases affecting the front and sides of the brain. It can show up first as changes in behaviour or language rather than memory. Read more in What Is Frontotemporal Dementia?
Mixed dementia is when more than one disease is present. It's more common than many people realise. The Alzheimer's Association describes an NIA-funded study in which most people who had been diagnosed with Alzheimer's during life were found, after death, to have at least one other type of brain change as well, most often blood vessel disease. The WHO also notes that the boundaries between types aren't always clear.
Why the Difference Matters
If the symptoms look similar, why does the label matter? Four reasons.
1. Treatment options depend on the type
Some medicines are specific to certain types of dementia. Two newer treatments, lecanemab and donanemab, are approved in the US for early Alzheimer's disease, meaning mild cognitive impairment or mild dementia due to Alzheimer's, in people with confirmed amyloid build-up in the brain.
The Alzheimer's Association notes they can slow decline but don't restore memory that's been lost.
Someone with vascular dementia would not be a candidate for these drugs. Managing blood pressure and cholesterol might be a bigger part of their plan instead, which the WHO highlights as a way to prevent further damage.
2. What to expect can differ
Different diseases affect different parts of the brain, so the early symptoms and the way things change over time can vary. Knowing the type helps families understand why Dad is struggling with words while his memory seems fine, or why Mum's personality has changed more than her recall.
3. It shapes planning and support
An accurate diagnosis opens doors: clinical trials, specialist services and programs such as Medicare's GUIDE Model, which supports people living with dementia and their family caregivers. It also gives the person a chance to make their own legal and financial plans early. Our guide on what to do after a dementia diagnosis walks through the first steps.
4. It helps everyone talk about it accurately
When the whole family understands what's going on, conversations get easier. Children, siblings and friends can learn what to expect and how to help, instead of guessing.
Whatever the type of dementia, daily life still needs support. Elli Cares helps with medication and appointment reminders, daily wellbeing check-ins and a shared care circle for family. Downloadable GP reports mean you can walk into appointments with a record of what's actually been happening between visits, which makes those diagnosis and follow-up conversations more useful.
Getting an Accurate Diagnosis
Diagnosis usually starts with the family doctor, who will look at the person's history, check for other causes of symptoms and may refer on to a specialist. Tests can include memory and thinking assessments, blood tests and brain scans. Our step-by-step guide to memory assessments explains what happens.
Useful questions to ask the doctor:
What type of dementia do you think this is, and how sure are you?
Could more than one cause be involved?
Are there other conditions we should rule out?
Which treatments might be suitable, and what are the risks?
What changes should we watch for, and when should we come back?
What support is available locally for the person and for family?
It's fine to ask for a second opinion, and it's fine for the diagnosis to be refined over time as symptoms become clearer.
Frequently Asked Questions
Is Alzheimer's the same as dementia?
No. Dementia is a term for a group of symptoms. Alzheimer's disease is the most common cause of those symptoms, contributing to an estimated 60 to 70 percent of cases.
Can you have dementia without Alzheimer's?
Yes. Vascular dementia, dementia with Lewy bodies and frontotemporal dementia are all types of dementia that aren't Alzheimer's. Many people also have more than one type.
Which is worse, dementia or Alzheimer's?
That isn't really the right comparison, because Alzheimer's is a type of dementia. How dementia progresses depends on the underlying cause, the person's other health conditions and many individual factors.
Is dementia a normal part of ageing?
No. It becomes more common with age, but the WHO is clear that it's not an inevitable part of getting older.
The First Step Toward Better Care
Knowing the difference between dementia and Alzheimer's isn't about getting the vocabulary right. It's about asking better questions, getting the right support and planning with confidence. If you're supporting someone at home, you can see how Elli helps families day to day on our Seniors and Families page.
