What is dementia?

What is dementia?

Dementia is a disorder that affects how the brain works. Symptoms of dementia vary from person to person, but can include:

  • loss of memory

  • difficulty thinking things through and understanding

  • problems with language (reading and writing)

  • confusion and agitation

  • hallucinations and delusions

  • difficulty controlling movements of the body.

Symptoms of dementia usually get worse over time and can become very severe, so that it is difficult for the person to do many daily activities or to care for him or herself.

Dementia is more likely to affect older people, but younger people can also develop the condition.

Types of dementia

There are different types of dementia; the most common are:

  • Alzheimer's disease

  • vascular dementia

  • dementia with Lewy bodies

  • frontotemporal dementia.

Dementia with Parkinson's disease is similar to dementia with Lewy bodies and some of the recommendations on dementia with Lewy bodies may be relevant to it as well. NICE has also produced a guideline specifically on Parkinson's disease.

There are also other types of dementia, but these are not covered specifically by the NICE–SCIE guideline or this information.