Communities need to look after people with dementia because too often they feel trapped and cut off from everyday local life, a charity says.
One in three people over the age of 65 develop the disease, but the Alzheimer’s Society says this large group is neglected by society.
It sought the views of 510 dementia patients and their carers.
A third of the patients said they left their home just once a week, and one in 10 said they got out only once a month.
Almost half avoided getting involved with local life because they felt they were a burden, and less than half felt part of the community.
A separate YouGov survey of more than 2,000 adults found most thought dementia patients’ level of inclusion of in the community was fairly or very bad.
The Alzheimer’s Society is campaigning for towns and cities to become “dementia-friendly”.
This includes opening up leisure activities to people with dementia and ensuring local transport services cater for their needs.
Shops and businesses should also train their staff to recognise and deal with customers who have dementia.
Lorraine Botbol, who cares for her mother who has dementia, called for more understanding about the disease.
“We took Mum out recently to a local supermarket because she used to love shopping,” she said.
“We always have a problem when we get to the cash desk.
“Mum is sometimes vocal and it often irritates people in the queue or sometimes even the cashier.
“This time, my mum got upset, and the cashier said she’d rather be dead than have dementia.
“It really upset me.
“You can’t just turn your back on people when they have dementia.
“My mum still enjoys activities and I wish people would wise up and understand you still need to value person when they have dementia.
“They’re still there, they just express themselves differently.”
Jeremy Hughes, chief executive of the Alzheimer’s Society, said it was shocking and saddening that so many people with dementia felt trapped and cut off.
“By committing to change, communities can give people with dementia the confidence to be part of local life and stay independent for longer.
“It’s vital that people sign up to the recognition process to kick-start this movement and help change attitudes and behaviour.”
Health Secretary Jeremy Hunt said the government was committed to backing initiatives to help manage dementia.
In December, the UK will use its presidency of the G8 to hold the first global dementia summit.
Two-thirds of people with dementia live in the community, and a third of these are living on their own.
The number of people with dementia is increasing because people are living longer.
It is estimated that by 2021, there will be about a million people with dementia in the UK.