Carers Trust, which released its findings to mark Young Carers Awareness day, said many children remain "invisible" to support services, and schools are often unaware of their caring commitments at home.
It follows a report published last month by Barnardo's that claimed schools were failing young people who cared for sick or disabled family members. Its study found that 40 per cent of teachers were "not confident" they would be able to identify a young carer in their class.
Carers Trust, which surveyed 50 young carers aged five to 10, as well as its network partner service managers who support nearly 1,000 young carers, found 46 per cent were missing out on sleep after getting up in the night to care for family members.
More than 80 per cent were also carrying out caring duties every day or most days of the week and three-quarters of these children said they provided emotional support to family members when they were sad.
The charity said while a sharp rise in the number of very young carers - nearly 10,000 under the age of eight performing unpaid caring duties - indicated that more young carers are being identified, many still remain hidden.
Giles Meyer, chief executive of Carers Trust, said: "It is a tragic situation that children who have barely started school are losing sleep that is so significant to their development and, in the night time, being exposed to and handling issues such as their siblings or parents' panic attacks or epileptic seizures when they should be getting important rest."
Meyer said that when young carers are identified, they do not receive enough support often due to confusion over whether services providing this help to young children are required to register with Ofsted.
"Funding and resources for one-to-one counselling sessions for children and giving families the option of young carers attending respite and activity days away from the pressures of home make a huge difference to families in these circumstances," he said.
Last month, children's charity Barnardo's claimed schools were failing young people who cared for sick or disabled family members.
A Department for Education-led plan to improve the identification of children and young who have caring responsibilities was announced in 2016 and a cross-government strategy was due to be published last summer.
However, despite calls from charitable organisations supporting young carers for the new Carers Strategy to be delivered, it has yet to be published.
