What is Dementia?

The word dementia describes a set of symptoms that may include memory loss and difficulties with thinking, problem-solving or language. These changes are often small to start with, but for  someone with dementia they have become severe enough to affect daily life. A person with dementia may also experience changes in their mood or behaviour.

Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease or a series of strokes. Alzheimer’s disease is the most common cause of dementia but not all dementia is due
to Alzheimer’s. The specific symptoms that someone with dementia experiences will depend on the parts of the brain that are damaged and the disease that is causing the dementia.


Each person is unique and will experience dementia in their own way.  The different types of dementia tend to affect people differently, especially in the early stages. How others respond to the person, and how supportive or enabling the person’s surroundings are, also greatly affect how well someone can live with dementia. A person with dementia will have cognitive symptoms (problems with thinking or memory). They will often have problems with some of the following:

    • Day-to-day memory – difficulty recalling events that happened recently
    • Concentrating, planning or organising – difficulties making decisions, solving problems or carrying out a sequence of tasks (eg cooking a meal)
    • Language – difficulties following a conversation or finding the right word for something
    • Visuospatial skills – problems judging distances (eg on stairs) and seeing objects in three dimensions
    • Orientation – losing track of the day or date, or becoming confused about where they are.

As well as these cognitive symptoms, a person with dementia will often have changes in their mood. For example, they may become frustrated or irritable, withdrawn, anxious, easily upset or unusually sad. With some types of dementia, the person may see things that are not really there (visual hallucinations) or believe things that are not true (delusions).

Dementia is progressive, which means the symptoms gradually get worse over time. How quickly dementia progresses varies greatly from person to person. As dementia progresses, the person may develop behaviours that seem unusual or out of character. These behaviours may include:

    • Repetitive questioning
    • Pacing
    • Disturbed sleep patterns or agitation

They can be distressing or challenging for the person and their carer. A person with dementia, especially in the later stages, may have physical symptoms such as muscle weakness or weight loss. Changes in sleep pattern and appetite are also common.

Helpful Leaflets to Download

What is Dementia? Factsheet

What is Alzheimers? Factsheet

Understanding and Supporting someone with Dementia. Factsheet

You can also click on the link to visit the website: Dementia

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