The Alzheimer's Society is the UK's leading care and research charity for people with dementia, their families and carers. They produce information and advice sheets to support those affected by dementia. Dementia with Lewy bodies (DLB) is a form of dementia that shares characteristics with both Alzheimer’s and Parkinson’s diseases. It may account for 10 to 15 per cent of all cases of dementia in older people. This information sheet outlines the symptoms of DLB, how it is diagnosed and how it is treated.