Dementia is not a disease in itself. Dementia is a word used to describe a group of symptoms that occur when brain cells stop working properly.

This happens inside specific areas of the brain, which can affect how you think, remember and communicate.

Alzheimer’s disease is the most common cause of dementia, but there are other types of dementia too. It is possible to have more than one type of dementia at the same time. Alzheimer’s is sometimes seen with vascular dementia or dementia with Lewy bodies. You might hear this called ‘mixed dementia’.

On these pages you will find information about the most common forms of dementia, including symptoms, diagnosis and treatments. This is not intended to replace the advice of doctors, pharmacists or nurses, but provides some background information which we hope you will find helpful.

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Alzheimer’s disease

The word dementia is used to describe a group of symptoms – these include memory loss, confusion, mood changes and communication difficulties. Dementia is caused by diseases that affect the brain. Alzheimer’s disease is the most common cause of dementia.


Young onset dementia

The word dementia is used to describe a group of symptoms – often including, but not limited to, thinking problems, confusion or mood changes. Although often thought of as a disease of older people, it is estimated that at around 42,000 people with dementia in the UK are under 65.

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Vascular dementia

Vascular dementia is the second most common type of dementia, for every 100 people with dementia, 20 of those will have vascular dementia.

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Dementia with Lewy bodies

Dementia with Lewy bodies is the third most common cause of dementia.

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Frontotemporal dementia

Frontotemporal dementia also called FTD, is a rarer type of dementia caused by a build up of proteins, tau, FUS and TDP-43, in the frontal and temporal lobes of the brain.

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Mild cognitive impairment

Mild cognitive impairment or MCI is a condition where people experience memory and thinking problems. It is not a type of dementia but for some people it can lead to the development of diseases like Alzheimer’s.

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Posterior cortical atrophy

Posterior cortical atrophy, also known as PCA, is an uncommon type of dementia that usually begins by affecting a person’s vision.


Primary progressive aphasia

Primary progressive aphasia (PPA) is a rare type of dementia. It is caused by damage to parts of the brain that control our language, personality, emotions and behaviour.

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Rare causes of dementia

There are several rarer conditions that can lead to dementia or dementia-like symptoms. Around 35,000 people in the UK are thought to be affected by these rarer causes of dementia.