Loneliness and isolation are some of the most significant issues facing older people, a group of AMs have said.
Half a million people in Wales say they feel lonely often or always, and not just elderly people, according to evidence given to the assembly's health and social care committee.
It wants the Welsh Government to publish its proposals to tackle the issue before planned in 2019.
The Welsh Government said it saw tackling loneliness as "a priority."
Wales has a higher proportion of older people than any other part of the UK, a report by the committee said.
Veterans, new parents, people recently bereaved and carers are some of the groups who may experience loneliness.
AMs took evidence from medical experts who said loneliness was not just about the size of social circles but often about the quality of people's relationships.
It is believed there could be many more people of all ages experiencing loneliness and isolation, because of the stigma attached to it.
One estimate puts the cost of isolation and disconnected communities in Wales at £2.6bn a year.
The report said a significant factor was a lack of public transport, especially in "cut off" villages as well as the short-term nature of funding for groups run by voluntary organisations.
Pat Berry, 82, from Newport, said she experienced loneliness after her husband died two years ago.
She attends a volunteer-run social group for older people at Maindee Library which she said was "very important" in helping her meet new friends.
"To have company for a couple of hours, to talk, because I don't see anybody," she said.
"I think 'hurry up Wednesday, I'm going to have company for a couple of hours'."
Ada Ridsdale, 92, said her life was "terrible" and she became "very depressed" after her husband died.
"You don't know what to do with yourself. I go into town every day and have a coffee so I can speak to someone," she said.
"I think people can sense that you're lonely because you're quiet, you're not outgoing."
The committee described the Welsh Government's plans not to publish its strategy to tackle the issue until 2019 as "disappointing".
"Wales has a higher percentage of older people within its population than any other part of the UK and often this means people are more reliant on social services and have more complex needs," said committee chairman Dai Lloyd AM.
"The effect of loneliness and isolation is profound, it can have both mental and physical consequences," he said.
"That the Welsh Government isn't planning on publishing its strategy to tackle these issues until 2019 isn't good enough and we call on ministers to speed up that timetable."
Age Cymru said its research showed nearly 300,000 older people feel their days can be repetitive, while 75,000 said they were not looking forward to Christmas.
"Much of this isolation stems from cut backs in local services such as buses, day centres and even street lighting, forcing many older people to remain trapped in their own homes, which can lead to a deterioration in both physical and mental health," said Age Cymru's Michael Phillips.
Claire O'Shea, Wales' Campaign to End Loneliness manager, said the country could "lead the way" in addressing loneliness by building "connected, resilient communities".
"There are many high-risk communities in Wales that will be impacted by the epidemic of loneliness, and we cannot wait until 2019 to see decisive action taken," she said.
In response, a spokesman for the Welsh Government said tackling loneliness and isolation "is a priority for us" and it had developed "a number of programmes and initiatives to help tackle this problem", such as funding and support for Ageing Well in Wales.
"We are also committed to taking further cross-government action to address this important issue," the spokesman added.