Dementia patients in UK hospitals face "Russian roulette" in the quality of their care as a new report highlights shocking standards in some NHS Trusts.
Some patients were ignored for hours on wards, denied food and pain relief while almost 5,000 with the condition were discharged from hospitals in the middle of the night.
The findings by the Alzheimer's Society also described cases of patients being manhandled or even handcuffed to beds.
Research involving more than 500 people affected by dementia found "a litany of failures," the charity said, with patients treated with "excessive force," left in wet or soiled sheets, and without help to eat or drink.
Jeremy Hughes, chief executive of Alzheimer's Society, said: "In the worst cases, hospital care for people with dementia is like Russian roulette. People with dementia and their carers have no way of knowing what's going to happen to them when they are admitted."
He said the failings uncovered could have "devastating, life-changing consequences."
In addition, Freedom of Information (FOI) disclosures from 68 trusts showed 4,926 people with dementia were discharged at night.
This has in the past raised concerns among health experts after cases where vulnerable people are forced to make their own way home
The report also highlighted cases where patients with dementia were left without the right pain medication, left alone on wards or busy A&E departments for hours and denied visits from family carers.
A Department of Health spokesman told the Daily Telegraph that the disease was a key priority and in recent years £50m had been spent on making hospitals and care homes more "dementia friendly", while 500,000 staff had received extra training.
Meanwhile Professor Alistair Burns, NHS England's national clinical director for dementia, told the Daily Mail: "There have in fact been major advances in recognising and assessing symptoms of possible dementia in patients admitted to hospital, with more than four fifths of trusts meeting a challenging 90% target."