There has been a "marked rise" in the length of time elderly people are held up in hospital while they wait for social care, a charity has warned.
Age UK said that, since June 2010, the NHS has lost almost two million "bed days" due to patients unable to be discharged because they are waiting for social care assessments, a care home place, a care home package or adaptations to be made to their own homes.
The delayed discharges have cost the health service £526 million, the charity said.
It has estimated that older people are now waiting, on average, one day longer in hospital before finding a place in a residential care home compared with 2010. The latest figures suggest that patients who need to be transferred to a residential home are waiting an average of 30 days.
Meanwhile, during 2013/14, those who needed adaptations to their own homes, such as grab rails or ramps, waited 27.3 days before discharge - 11.5% longer than in 2010, Age UK said.
And those needing a social care package to be put together before they can go home are having to wait an average 28.6 days - 5% longer than four years ago, a charity spokeswoman said.
She said the delays are occurring against a backdrop of cuts to social care funding since 2010.
"Because of this underfunding, access to publicly funded social care has also become increasingly restricted, with the vast majority of local authorities now only able to provide help if a person's needs have been assessed as being 'substantial' or above," the spokeswoman said.
"Many older people who struggle with everyday tasks such as getting out of bed and dressing, bathing, preparing meals or doing the shopping are assessed as only having 'low' or 'moderate' needs and so do not qualify for any help at all.
"This absence of support leaves many older people at risk of a crisis."
Caroline Abrahams, charity director of Age UK, said: "The marked rise since 2010 in the length of time people are being forced to linger in hospital because of a delayed assessment, care home place, home care package or home adaptation is an outcome of the crisis in social care.
"It is crazy to waste expensive NHS resources in this way, when it would be much more cost-effective and better for older people to fund social care properly instead.
"Waiting in hospital a month or more for social care to be organised can also undermine an older person's chances of recovery and be profoundly upsetting for them and their families too.
"Investing in social care would unblock the logjam and help our hospitals to work more efficiently. A properly resourced care system would transform many older people's lives for the better and would make financial sense as well.
"The best thing the Government could do today is to say they will set the national eligibility criteria for social care at a generous level and commit the increased funding this requires. Then we could have a reasonable expectation that these terrible delayed discharge figures can be improved."