More than one-fifth of elderly people feel they are living in poverty, a Help the Aged survey has suggested.
The number of elderly people in the UK is set to rise
Of 1,095 adults questioned, 28% said their quality of life had got worse in the last 12 months, while 93% said their lives had not improved.
The charity said the findings were "outrageous" and called for a clear commitment to end pensioner poverty.
Around half of over 65-year-olds fail to claim the benefits they are entitled to, the survey also found.
Help the Aged said that its report, Spotlight on older people in the UK, brought to light issues faced by vulnerable older people, including poverty, neglect and ageism.
A total of 13% of those surveyed said they were lonely and rarely left the house.
The study, the second annual report from Help the Aged, suggested 21% of elderly people lived in poverty and rising fuel bills made life a daily struggle.
It includes testimonies from a woman in her late seventies who says her quality of life is nil, a woman aged 87 who says she never leaves the house, and an old man who thinks a tin of soup is a luxury to eke out over two days.
Paul Cann, director of policy at the charity, said: "Far from being people's twilight years, this report shows the reality of growing older in the UK is much darker.
"It is absolutely outrageous that people's lives are getting worse or not improving as they get older."
The charity said with the number of people aged 65 years and older set to rise by nearly 60% in the next 25 years, there was no excuse for the government or anyone else to be oblivious of the issues.
"If steps are not taken to enable people to carry on working and saving, to improve public health, and to ensure that adequate social care is available for those who need it, growing numbers of people will be blighted by disadvantage in older age," Mr Cann said.
"With so many older people already leading unfulfilled lives, there is no time to lose."
He added that much more could be done to help older people get out and about, such as providing better transport, shops, post offices, and public toilets.
The survey also suggested that 47% of pensioners failed to claim the Council Tax benefit which they were entitled to.
Help the Aged also called for a new government strategy which meant elderly people would be paid benefits automatically.