The social care system would collapse without unpaid carers - who contribute the equivalent of more than four million jobs in the sector, a report has warned.
Health think tank The King's Fund made the claim as it called for more support for the nation's army of uncompensated workers - who include 1.5 million people in England alone who provide 50 or more hours of care a week to loved ones.
The report also pointed to research which found only 27% of carers currently receive paid support such as direct payments, personal budgets and commissioned support - a drop from 31% in 2015/16.
And the numbers provided with respite care delivered to support their carers have also fallen from 57,000 in 2015/16 to 33,000 in 2021/22.
That is despite unpaid carers contributing close to eight billion hours of social care each year, the report said.
The findings come just weeks after research which claimed that the value of unpaid care in England and Wales is almost equivalent to a second NHS, saving the government £162bn per year.
The strain is particularly tough on full-time carers such as Tania Tillyer, who has spent almost all her adult life looking after her son Lee.
He was a born a healthy baby - but when he was one years old, a life-threatening infection closed off his airways and stopped blood from reaching his brain.
It left him quadriplegic, blind and with severe earning difficulties.
Lee, who is now 38-years-old, is almost entirely reliant on his mother's care.
But as Tania grows older she worries about her own health and her ability to continue caring for her son.
"It's very challenging," Tania says.
"When you're younger, it's relatively easy because you're just caring for a child, aren't you? But then that child grows up and gets bigger and heavier.
"And then you're caring for an adult and the whole system changes. I'm nearly 40 years older than when I had Lee and I have my own health needs.
"That means it makes it extremely difficult to care for Lee physically, you know, because it requires a lot of moving, handling and lifting onto the bed, to changing, getting dressed, getting washed and things like that.
"And I'm finding that really, really difficult at the moment."
Workforce shortages in the care sector impact on carers' health and wellbeing because they are the ones left to fill in the gaps.
The 2021 Census found that an estimated 4.7 million people in England provided some kind of unpaid care in 2021, equivalent to 9% of the population. Around 1.7 million provide less than nine hours a week, the report said.
Tania gave up work to become a full-time carer and her husband is self-employed. That means when he takes time off to help to care for Lee he does not get paid. It all adds to the family's anxiety.
Tania said: "You have the financial worry because you're not getting paid because you can't work.
"That is difficult and my husband's self-employed.
"If we have hospital appointments or if anything's going on with Lee that requires him to be here, then he doesn't get paid when he's at home, helping me.
"It's stressful and it is difficult. I think all carers would benefit from a higher carers' allowance. I know that things have improved greatly, but I think it does need more improvement in terms of giving carers paid leave.
"So that when the person that they're looking after requires them, they actually get paid for being at home because it's not like getting somebody to babysit.
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"You know, a lot of children and young people like Lee require 24/7 care. And you have to have the right people caring for them.
"It's not somebody you can just drop off somewhere.
"You have to be there as well for them which means you need someone to keep you financially viable so you can keep going and keep a roof over your head."
Deborah Fenney, a fellow at The King's Fund and co-author of the report, said: "Staff in local health and care systems work hard to support unpaid carers, and there's a lot that can be done to improve that support.
"It's vital that local services understand who these carers are and the kinds of support they need - and crucially, engage with local unpaid carers to do this."
"Our report highlights that unpaid carers contribute the equivalent of four million paid care workers to the social care system and without them the system would collapse.
"Carers say they often struggle to find out what support is available, and it is a complex system to navigate.
"On top of this they are experiencing pressure from the wider issues the health and social care sector is currently facing.
"Unpaid carers said repeatedly that what most mattered to them - and what would make the greatest difference to their lives - was an improvement in the quality and extent of the care being provided for the person they were caring for."
A government spokesperson said: "Unpaid carers play a vital role in our communities, and we all owe them a debt of gratitude.
"We've earmarked £327m through our Better Care Fund this year to support local authorities with health and care services, including providing carers with advice, support and short breaks and respite services.
"We continue to provide financial support to unpaid carers through carer's allowance, and we are finalising plans for how we deliver up to an additional £25m to support carers and hope to share those shortly."