Alzheimer's Society is a United Kingdom care and research charity for people with dementia and their carers. It operates in England, Wales and Northern Ireland, while its sister charities Alzheimer Scotland and Alzheimer's Society of Ireland cover Scotland and the Republic of Ireland respectively. It is a membership organisation, which works to improve the quality of life of people affected by dementia in England, Wales and Northern Ireland. Many of the 25,000 members have personal experience of dementia, as carers, health professionals or people with dementia themselves.