An attempt to capture the current health of children has highlighted a grim picture of rising dental disease, skin infections and breathing problems.
Cure Kids, which today releases its first annual State of Child Health report, says hospital admission rates are on the rise for under-15s and will only get worse unless action is taken.
Mother-of-four Stacey Kale has twin girls Grace and Amelia who were born premature with chronic lung disease.
Now 3 years old, they make regular trips to hospital and face the prospect of going into ICU if they come into contact with anyone who is sick.
Stacey said the family home has been made dry and warm and she's urging others with sick kids to do the same.
"We just have to make sure we're really careful ... it's people that are not staying home or looking after things early ... if they stay home and actually get better instead of being out in the community spreading things because there's so many people that are just so vulnerable and really struggle to fight it," she said.
Data collated from hospital admissions, the New Zealand Health Survey and oral health bodies show child dental disease, respiratory conditions and skin infections are all on the rise.
Rates of hospital admissions are highest among Māori and Pasifika children, as well as kids under 5.
Cure Kids' chief executive Frances Benge called it grim reading.
She said around 40,000 New Zealand kids go to hospital every year with preventable illnesses.
"Look, some of the barriers include the physical lack of access - so distance, poor health understanding, poor living conditions, lack of nutrition," she said.
Fewer than 60 per cent of children brush their teeth at least twice a day with fluoride toothpaste.
Around four in 10 of all Kiwi 5-year-olds suffer some form of tooth decay.
Benge said without intervention, hospital visits for tooth decay would only get worse.
"There's really poor teeth brushing practice and that's right across all of New Zealand children - so that's definitely something that education, and health prioritisation and research into why our children are vulnerable to tooth decay can be turned around," she said.
Respiratory conditions are the leading cause of acute admissions to hospital, with parents fretting over common signs such as coughs and wheezing.
Auckland senior paediatrician Simon Rowley said early life conditions could eventually lead to more serious illnesses.
"Tooth decay can lead to such serious general health - particularly cardiac - but also the way kids feel - and bloodstream-born infection," he said.
The research was conducted by Otago University.
Director and clinical epidemiologist Dr Mavis Duncanson said a strong public health system should be able to promote and improve kids' health.
"There are serious issues that we do need to attend to in terms of enabling every child to live their best life and to enjoy the health that should really be their right," she said.
Next year's research will focus on kids' mental health, obesity and nutrition.