Too many people avoid talking about getting old, particularly conversations about end-of-life care, suggests a survey by a charity for older people.
Two out of three adults aged over 65 in the study said they had never talked to their family about the issue.
But Independent Age said cuts to social care budgets meant it was more important than ever for families to talk about the future.
One in four over-65s said they were not planning to broach the subject at all.
This group also said they were not planning to discuss issues such as who would care for them and where they would live if they could no longer look after themselves.
Around 2,000 adults completed an online questionnaire for the research.
Although 82% of adults recognised it was important to talk to older relatives about issues of ageing, only a minority had actually had these conversations.
This tended to be because they didn’t want to face up to the issue, didn’t know how to start the conversation or didn’t want to upset their relatives.
But the charity warned that families risked making rushed decisions about care, health, housing and financial matters if they didn’t starting talking.
It has launched a new online guide to help families broach the potentially difficult subject of ageing.
Janet Morrison, chief executive of Independent Age, said: “For many families, having these conversations will never be easy. For older people, it can mean facing the prospect of losing independence.
“For their relatives, it can mean facing the thought of losing a loved one or feeling overwhelmed by a sense of responsibility.
“But these are issues that only get more pressing with time. It is vital that families start talking about these issues now, so they’re not left making important decisions at times of crisis or suddenly struggling to cope with significant caring responsibilities.”
She added that an ageing population meant that fewer people were receiving care from local councils and were more reliant on informal care from family members.
It is estimated that the number of older people living with a disability will rise from 2.9 million to 4.8 million between 2015 and 2035.
Over the same time period, the number of disabled older people receiving informal care is projected to increase from 2.2 million to 3.5 million.