There were almost 10,000 safeguarding concerns raised about vulnerable adults in Cornwall last year, new figures show.
Age UK said a shortage in good quality care could have "miserable consequences" for older and disabled people, if it is not addressed by Government.
NHS figures show 9,065 concerns of suspected abuse were made about adults with care and support needs in Cornwall in the year to March – an increase from 8,050 the year before.
Across England, there were nearly 588,000 safeguarding concerns raised – a 9% increase on the year before.
Caroline Abrahams, Age UK charity director, said: "At a time when our social care services are under such acute pressure it is not surprising that the numbers of reported incidents of abuse against older people are on the rise, and that the neglect of those living in their own homes form the largest category.
She added older people often wait months for a social care assessment, while home care agencies are stretched in finding staff to provide the support their clients need.
"These circumstances are a recipe for older people not to receive all or sometimes any of the care and support they require," she said.
"We know from our own contacts with older people and their families that this leaves some living in intolerable situations, with risks to their health as well as their wellbeing."
Ms Abrahams added the figures are a reminder of why the Government must address the "shortfall of good quality social care" in England, and of the "miserable consequences" for older and disabled people if it is not addressed.
If councils believe a vulnerable adult is experiencing or is at risk of abuse or neglect, they must carry out a Section 42 enquiry to determine whether action should be taken. The very elderly – those aged 85 and over – are most likely to be the subject.
The data shows there were 1,315 Section 42 enquiries concluded in Cornwall last year.
The council found that the highest proportion of allegations in the area were linked to psychological abuse (22%), while the highest number of incidents took place in the alleged victim's own home (63%).
Nationally, most incidents were also likely to happen at home while allegations of neglect were at the centre of most investigations.
A Department of Health and Social Care spokesperson said: "Abuse of any kind – especially against vulnerable people in care – is abhorrent and we’re taking measures to protect people including through comprehensive inspections.
"Across the country, the police, councils and the NHS are working together to help protect vulnerable adults from abuse or exploitation."
If an older person is in immediate danger, the police can be called on 999.
People can also call Hourglass on 0808 808 8141, a charity dedicated to ending the abuse of older people or Age UK's advice line on 0800 1696565 to seek advice about concerns.