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Dementia is a syndrome (a collection of symptoms) that causes a decline in mental ability. This decline can be characterised by memory loss, difficulty reasoning, concentrating and communicating, and can also lead to a reduction in a person’s abilities to perform activities such as washing, dressing and cooking.

Dementia occurs due to the death of brain cells or damage in brain areas associated with memory and thought processing. Although the cause of the death of such brain cells is not completely understood it may follow other problems such as a lack of blood or oxygen supply to these brain areas, pressure on the brain (from a tumour, for example), and neurological disease or infection (such as Parkinson’s disease, Creutzfeld Jakob disease (CJD) and AIDS).

The most common type of dementia is Alzheimer’s disease. Alzheimer’s disease is a form of degenerative dementia, meaning that the symptoms will progressively get worse. However, vascular dementia, the second most common type of dementia that is a result of mini strokes constricting blood flow and oxygen to the brain, is non-degenerative and may not get worse over time.

People with dementia can become confused, restless, and may also sometimes seem irritable, tearful or agitated. This can lead to difficulties with planning and organising.

According to the Alzheimer’s Society there are around 850,000 people in the UK with dementia. One in 14 people over 65 will develop dementia, and the condition affects 1 in 6 people over 80. The number of people with dementia is increasing because people are living longer. It is estimated that by 2025, the number of people with dementia in the UK will have increased to around 1 million.

To access up to date information on signs, symptoms and treatment guidance click on the links below:

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