A care time bomb is ticking with the number of older people affected by chronic conditions and disability set to soar in the next eight years, experts have warned.
Scientists estimate that by 2025 there could be 2.8 million people over 65 years of age needing care in England and Wales - a 25% increase since 2015.
They are calling for urgent disease prevention policies aimed at improving diet, reducing alcohol consumption, helping smokers to quit, and targeting high blood pressure and physical inactivity.
The shortage of caregivers and poor state of social care also had to be addressed to prevent dependent people on lower incomes suffering severe hardship, said the authors of a new study published in The Lancet Public Health journal.
Currently, 40% of the national cost of long-term care is paid for by the personal savings and incomes of affected individuals and their families.
Lead researcher Dr Maria Guzman-Castillo, from the University of Liverpool, said: "The societal, economic, and public health implications of our predictions are substantial. In particular, our findings draw attention to the scale of societal costs associated with disability in the coming decade.
"Spending on long-term care will need to increase considerably by 2025, which has serious implications for a cash strapped and overburdened National Health Service and an under-resourced social care system.
"More cost-effective health and social care provision will be needed, such as increased availability of institutional care, and better financial support - such as tax allowances or cash benefits - for family members providing informal and home care."
The study modelled future trends in disability and life expectancy in England and Wales between 2015 and 2025, taking into account predicted rates of heart and artery disease, dementia and other conditions.
The proportion of the population over 65 was expected to rise by almost a fifth (19%) from 10.4 million to 12.4 million over the decade.
For people aged 65 in 2025, average life expectancy was projected to increase by 1.7 years to 86.8 years compared with what it would have been in 2015. But a quarter of remaining life after 65 was likely to be spent coping with disability, said the researchers.
Overall, dementia was the biggest disability threat with rates expected to increase by 49% among people aged 65 and over.
In 2025, an estimated 699,000 people in England and Wales were likely to have dementia care needs compared with 468,000 in 2015.
Other care burdens including mental health problems, diabetes, and musculoskeletal disorders were predicted to increase by 37%. Among the over-85s, they were set almost to double.
Co-author Professor Eric Brunner, from University College London, said: "Our new forecasting model uses real-life evidence to assess the future impact of the competing forces that give rise to loss of health and well-being in older people in our country.
"We find that ageing of the population in the next 10 years will cause an increase in burden of disability that we must not ignore."
Royal College of GPs chairwoman Professor Helen Stokes-Lampard said: "It's a great testament to medical research, and the NHS, that we are living longer - but we need to ensure that our patients are living longer, with a good quality of life.
"For this to happen, we need a properly funded, properly staffed health and social care sector with general practice, hospitals and social care all working together, and all communicating well with each other, in the best interests of delivering safe care to all our patients.
"But as well as more resources, we agree with the authors of this study that prevention of chronic diseases that can have a serious effect on a patient's quality of life is key, and this is something for which we all bear responsibility."