It's taking almost a decade for New Zealanders with endometriosis to get an official diagnosis

According to research from Canterbury University and Endometriosis NZ, the average diagnosis delay is 9.7 years per patient - an increase of 11 percent in two years.

It found delays were longer in the North Island than the South.

Endometriosis NZ CEO Tanya Cooke says the findings are concerning - but not surprising.

She says they frequently hear about long delays - and many are longer than the average.