Young carers struggle without the help they urgently need, often due to fear that they may be separated from their families, a report suggests.
Many young carers are slipping through the net, Barnardo's says
At least 175,000 children and young people look after a parent or sibling - but charity Barnardo's says it believes that many more are going unsupported.
Its poll of 1,000 teachers found 91% felt many young carers had no help.
Of 83 young carers also surveyed, it had taken an average of four years before they received any support.
Barnardo's chief executive Martin Narey said: "They have huge responsibilities that most adults never have to face, some providing care for 30 hours or more a week.
"They often have to administer medicines, bathe parents, pay bills and be responsible for shopping for the family as well as looking after younger brothers and sisters.
"Without support they can miss out on childhood altogether."
The surveys are from Barnardo's Hidden Lives report.
The charity runs 14 projects supporting young carers, working with nearly 2,000 children and young people, but it fears there are many more young carers who are not captured by the official statistics.
Of the teachers questioned, nearly eight out of 10 believed that the relatives of young carers had deliberately not requested help for fear the family may be broken up.
The majority - 72% - thought that child carers hid their situation from teachers and that 75% did not tell their peers the truth about their home life.
Alongside the survey of teachers, Barnardo's spoke to 83 young people between the ages of six and 19 whom it supports.
Most cared for an average of 17 hours a week. Six carried out caring duties for between 30 and 40 hours a week.
On average each had spent four years looking after a relative or parent before receiving support. Five had cared for people for more than 10 years before getting help.
Teachers also acknowledged that they were often unaware that children could be young carers.
This tied in with the young carers' views - 42% of them saying teachers had not taken an interest in their home responsibilities.
Barnardo's is calling for schools to have a strategy to support young carers and to work with social services and health services.