Dementia Support Line
What is the difference between dementia and Alzheimer’s disease?
Dementia is a condition where problems with memory or other types of thinking make it hard for a person to do everyday activities by themselves. It can be caused by several different diseases that affect the brain. Alzheimer’s disease is the most common cause of dementia.
Alzheimer’s disease starts in the brain many years before symptoms start to show. Early symptoms are mild and so don’t stop someone doing their normal everyday activities. It’s only later that symptoms become severe enough to be called ‘dementia’.
Other common causes of dementia include vascular disease, which prevents blood from getting to the brain properly, and Lewy body disease.
Just as with Alzheimer’s, these diseases develop in the brain over many years. Eventually they lead to vascular dementia and Lewy body dementia.
What is dementia?
Dementia is a group of symptoms. It’s caused by different diseases that damage the brain. The symptoms get worse over time and include:
- memory loss
- confusion and needing help with daily tasks
- problems with language and understanding
- changes in behaviour.
Dementia is progressive, which means symptoms may be relatively mild at first, but they get worse over time.
What is Alzheimer’s disease?
Alzheimer’s disease is the most common cause of dementia. About two out of three people living with dementia in the UK have Alzheimer’s disease, which is sometimes called “Alzheimer’s”.
Alzheimer’s disease is a physical illness which damages a person’s brain. It starts many years before symptoms start to show.
Early symptoms of Alzheimer’s are mild and don’t prevent someone from doing everyday activities by themselves. This is called mild cognitive impairment (MCI).
It’s often not possible at this stage to say for sure that the person’s symptoms are being caused by Alzheimer’s disease, as there could be many other causes.
Eventually Alzheimer’s disease causes so much damage to the brain that the person develops dementia. Technically this type of dementia is called ‘Alzheimer’s disease dementia’. However, most people – including healthcare professionals – just call it ‘Alzheimer’s disease’.
For most people, Alzheimer’s disease starts in and around the part of the brain involved in memory. However, in some rarer types of dementia the disease starts in a different part of the brain and so causes a different set of symptoms. This is called ‘atypical Alzheimer’s’. For example, posterior cortical atrophy is caused by Alzheimer’s in the back of the brain and mostly causes problems with vision.
What causes Alzheimer's disease
The causes of Alzheimer’s disease are very complex, but one key part is the build-up of two substances inside the brain called amyloid and tau. When conditions in the brain aren’t right, these clump up and form tiny structures called plaques and tangles. These make it harder for the brain to work properly.
Over time the disease causes certain parts to become smaller. It also reduces the amount of important chemicals needed to send messages around the brain.
There is currently no cure for Alzheimer’s disease. However, treatments may temporarily ease some symptoms or slow down their progression in some people.
What are the main other types of dementia – and what causes them?
Vascular dementia: this the second most common type of dementia. It is caused by problems with the blood supply to parts of the brain.
Lewy body dementia: Lewy bodies are tiny clumps of protein that build up in the brain. When this happens, it leads to Lewy body disease. There are two main types:
- Dementia with Lewy bodies: When the first signs of Lewy body disease are symptoms of dementia, this is known as ‘dementia with Lewy bodies (DLB)’.
- Parkinson’s disease dementia: Lewy body disease can also cause Parkinson’s disease, which mostly involves problems with movement but can also lead to dementia several years later. If it does, this is known as Parkinson’s disease dementia.
Frontotemporal dementia: this is a less common type of dementia. It can be caused by several different types of disease but they all mostly affect the front or the sides of the brain, known as the frontal and temporal lobes.
Mixed dementia: A diagnosis of mixed dementia is generally used when someone has a mixture of clinical symptoms from two or more different types of dementia – for example, if they have symptoms of both Alzheimer’s disease and dementia with Lewy bodies.
How do I know what type of dementia I have?
A diagnosis of dementia needs to be made by a healthcare professional who specialises in dementia, usually following a detailed assessment at a local memory service.
When someone gets a diagnosis of dementia they should ideally be told by the doctor what type they have. This doesn’t always happen though. Sometimes it’s hard to tell what the cause of a person’s dementia is – particularly during the earlier stages.
It’s not always essential to know straight away what the cause of dementia is, but it can help to make better sense of the person’s symptoms and to get the right treatment.
Does Alzheimer’s Society support people with dementia, as well as Alzheimer’s disease?
We support anyone who has dementia. We can help guide people with mild cognitive impairment or who are worried about their memory. Find out how Alzheimer's Society can support you.
We’re a vital source of support, giving help to everyone who needs it today, and hope for everyone in the future.
This post was first published in July 2018 and most recently updated in February 2023.
Dementia Support Forum
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chloe
saysmy nana has recently been having brain scans and is waiting for her diagnosis but nurses have said its most likely going to be dementia. She's gone from a size 12/14 to a size 6 within a year. She is constantly forgetting family members and names and in my birthday card she wrote sentences that had random words in etc.
She has said to me she doesn't want to feel like this anymore and I feel lost In helping her as she just wants everything to be done with and I was in shock when she said that but I just don't know what to do.
Hi Chloe, thanks for getting in touch.
Sorry to hear about your nana's condition - it sounds like you're doing the right thing in seeking a diagnosis.
While you're waiting for a diagnosis, you can still call our National Dementia Helpline to speak with one of our advisers about the situation. They're available to chat seven days a week on 0300 222 11 22, and can give information, advice and emotional support: https://www.alzheimers.org.uk/get-support/national-dementia-helpline
Please don't hesitate to get in touch if you need support, for your nana or for yourself.
Best wishes,
Alzheimer's Society blog team
Joan fraser
saysmy father aged87 has mixed dementia. periodically he will stop speaking to mum over something stupid. this last time it has lasted 3days turning his back on her in his chair .usually he comes out of it quite quick .how can I help them both ??
Hello Joan, thanks for getting in touch.
We're sorry to hear you're going through such a difficult time with your father.
We recommend calling our National Dementia Helpline to speak with one of our advisers about your situation - they're available to chat seven days a week on 0300 222 11 22.
In the meantime, you may find it useful to read our information on behaviour changes and how to manage challenging situations: https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/sym…
We hope this helps, Joan.
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Alzheimer's Society blog team
KA Cobbold
saysThankyou exelent answers
Debra
saysMy mom was recently diagnosed mid point Alzheimer’s. She can get real hostile and she says things that aren’t true or never happened. I’m trying to find a support group in my area for me. I put my address on your website where it says to find, nothing
Hello Debra,
We're very sorry to hear about your mother's recent dementia diagnosis. It sounds like you're going through a very challenging time.
If you're based in the UK, please call our expert advisers through the National Dementia Helpline: https://www.alzheimers.org.uk/get-support/national-dementia-helpline They can talk through your mother's challenging behaviour, and can discuss support groups available in your local area.
In addition, Dementia Talking Point is a helpful online community where anyone who is affected by dementia can receive valuable support. It's free, open day or night, and can be accessed online: https://www.alzheimers.org.uk/get-support/dementia-talking-point-our-on…
If you're living outside of the UK, please take a look at Alzheimer's Association in the US (https://alz.org/), Alzheimer's Society Canada in CA (https://alzheimer.ca/en) or Dementia Australia in AUS (https://www.dementia.org.au/).
We hope this helps.
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Alzheimer's Society blog team
Nancy Danneberg
saysWe must continue to fight any impairment to our wonderful brain. Having a brain injury in a near fatal car accident years ago led me to believe the brain is a wonderful entity needing our support with proper nutrition and a positive outlook for its very survival. That happened over 40 yrs. ago. I was just told by my doctor, after seeing relative signs from a brain scan, that I had the start of dementia. At 71 yrs. I'll give it a good fight. That's all I can do, with the grace of a higher entity beside me.
Robert
saysThe information provided gave a cocise yet easy to understand the different types of dementia.
Celia Lansley
saysHi. I was a GP for15 years and have been out of the NHS and medicine for 13 years but am now retraining to be a GP again. I think your resource here is amazing. I've been moved to tears by the comments and the helpfulness of your answers. I will undoubtedly be referring patients to your website and blog, thank you so much
craig mathieson
saysThank you, my mum has vascular dementia and heart failure. When she took sepsis the hospital thought she would be too weak to fight it but she it. I was wondering about life span and cause of death and it helpful to know it will be from an infection or the like.
My dad has just been diagnosed with Alzheimers also. Having 2 parents in need of so much care as the diseases progress is going to be really tough for me. I need to take one day at a time and pray, hope and dont worry!
Mandy
saysHi my dad today has been diagnosed with dementia and Alzheimer’s what is the progression of these illnesses is it months or years thank u
Hi Mandy.
We're very sorry to hear about your dad's recent diagnosis. You might find this page helpful - 'The progression of Alzheimer's disease and other dementias': https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/how… This information is also available as a factsheet: https://www.alzheimers.org.uk/media/16701
In addition, if you're seeking further information, support or advice, please know our helpline is here for you on 0300 222 11 22.
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Alzheimer's Society blog team
Margaret Wilson
saysMy friend was diagnosed with frontotemporal dementia this week. I am meeting him on Saturday and have no idea what to say to him. I would love to have an honest and open conversation with him about it but am afraid of upsetting him. Any suggestions on how to approach the conversation would be appreciated.
Angela
saysHello my mother has vascular dementia and is now in her tenth year from being diagnosed.
Mam moved in with me and my husband 5 years ago and I am her main carer. It has been a tough ride from agitation issues aggressive behaviour a lot of years from us both and break ups in the family.
I don’t think a lot of people realise how stressful it is looking after a loved one with dementia. They call it the family dementia and I believe that to be true.
I will say however that the memory clinic help with changes in medication to help support mams behaviour so she feels less agitated.
Mam is at the stage now where she sits and needs help with mobility but we still keep her attending the day centre with her friends. Mam used to be a carer and loves being around people.
Mam is doubly incontinent and can not feed herself or lift a drink.
We take every day as it comes and try to fill it with music . I talk to Mam as normal as I know she can hear me and understand what I’m saying unfortunately mam can not speak a sentence and mumbles. Love is the answer and patience. We can’t ask for a miracle so we take what we’re given.
My heart goes out to all who are going through the same xxx aww and well done to you all it’s a tough ride
Georgie
saysHi, I'm trying to write a dissertation on Alzheimer's disease. I have found that some studies refer to "Alzheimer's disease (AD)" and some refer to "Dementia of Alzheimer's type (DAT)". Are these the same thing, or would DAT occur later on once AD has progressed and caused the symptoms that incur a dementia diagnosis? I know that if you have dementia, you don't necessarily have AD, but if you have AD does that mean you have dementia?
Hi Georgie, thanks for your comment.
The two terms are indeed strongly related. However, they come from slightly different perspectives.
‘Alzheimer’s disease’ is the underlying disease process that eventually leads to the collection of cognitive symptoms known as ‘dementia’. In terms of pathology, it’s characterised by an accumulation of abnormal proteins in the brain in the form of amyloid-beta and tau neurofibrillary tangles (amongst other things, but these are the big two).
A person may have AD going on in their brain for several years without experiencing any clinical symptoms but, providing they live long enough, the condition will eventually lead to cognitive impairment. When these cognitive symptoms are severe enough to interfere with daily living, the person with AD is said to have ‘dementia’. They will therefore have dementia, but of the Alzheimer’s disease type (DAT).
DAT isn’t a widely-used term from what I can tell, although it does pop up every now and then.
Best of luck with the dissertation!
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Alzheimer's Society blog team
Makunyapane B. Matubatuba
saysThe statistical prevalence rate is not frequently mentioned. I think it is also important to mention it.
Leah Bostick
saysMy Daddy remembers old things memories and sometimes thinks he is at a hotel he use to be a manager at hotels many he walks through the tv room trying to pick something up nothing there he loses demention of where he is walking oh my goodness I love my Daddy everyday a great day when I see him smile at me Sometimes he doesn’t know who I am
Karen Colley
saysMy sister in law has epilepsy she is 65 and has developed severe memory loss overnight the doctors have diagnosed dementia but there does not appear to be any treatment available .she can no longer live independently and as her carers my husband and I are now looking for information .
Hi Karen,
Sorry to hear about your sister-in-law's diagnosis.
We have a free publication called 'Caring for a person with dementia: a practical guide' which you may find helpful. It's quite comprehensive so hopefully you'll be able to find the information you need. The guide is available to download or you can order a print copy here: https://www.alzheimers.org.uk/get-support/publications-factsheets/carin…
If you're looking for information, advice or emotional support you can also call our helpline and speak to one of our advisers. The helpline's opening hours and details are listed here: https://www.alzheimers.org.uk/get-support/national-dementia-helpline
Hope this is helpful,
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Alzheimer's Society blog team