A doctor researching asthma says misdiagnosis can result in people practically fertilising bacterial infections.
The clinical director of medicine at Middlemore Hospital says Maori are more likely to turn up to emergency departments with asthma and take time off work because of the condition.
Jeff Garrett said too many people are misdiagnosed with asthma and given inhalers, when the cause of their breathing difficulty is a bacterial infection in the throat.
He said inhaling steroids will feed a bacterial infection and make it worse.
Dr Garrett said there should be more effort to target inflammatory cells with the right treatment.