Parents are being warned to be more vigilant in managing their child's asthma as winter approaches, with increasing numbers of children being hospitalised for the disease.
A new Massey University report shows the number of children hospitalised annually has nearly doubled since 2002, increasing from 473 per 100,000 to 688 per 100,000. In 2016, more than 6000 children under 15 were hospitalised.
Fifteen percent of all Kiwi kids are affected.
New Zealand was found to have one of the highest rates of asthma in the world, with around 70 people dying each year.
Otago University associate professor Jim Reid says one in nine adults in New Zealand don't grow out of the disease.
"While we don't fully understand why the rates of asthma are so high among New Zealand adults and children, more needs to be done to get asthma under control," he says.
"With the onset of cold and flu season, it is critical that adult asthmatics and parents watch out for asthma symptoms which may signal a potentially deadly attack."
Prof Reid says common triggers include a cold or virus, cigarette smoke, exposure to nitrogen dioxide from gas heaters and car exhausts and indoor dampness or mould.
"If asthmatics begin to exhibit an increasing wheeze that doesn't respond to a reliever inhaler which is usually blue in colour, they have difficulty speaking in full sentences or they begin to turn blue - these are all signs they need immediate medical intervention from a doctor."
More than 521,000 Kiwis are estimated to need medication for the disease.