An app for endometriosis sufferers is launching to help gather data on what those working with the disease are calling "a public health issue we can no longer ignore".

New York-based Kiwi researcher Sylvia English is part of a team developing a number of tools to better understand the condition, which is often misunderstood and can take years to diagnose.

The researchers behind the project, Citizen Endo, say they want to "bridge the research gap between patients' experience of endometriosis and clinical understanding of the disease".

Endometriosis affects an estimated 3 per cent of women in New Zealand, according to the Ministry of Health, and international studies put the number even higher, at one in ten women worldwide.


Despite this, its symptoms are often overlooked or misunderstood, meaning diagnosis can take years or even decades.

Women suffering endometriosis can experience crippling period pain and, in some cases, late diagnosis affects fertility.

English's project includes an app, Phendo, which endometriosis sufferers can use to track and manage the condition's symptoms.

"We decided to pursue the project because there is a knowledge gap when it comes to endometriosis," English said.

"We hope that by tracking the disease in a purpose-built app, women will begin to see trends in their experience to help them better manage the disease along with their care provider."

Endometriosis was an understudied disease with many pervasive myths surrounding diagnosis and treatment, English said.

Phendo, which is free to download, launched earlier this week.

"Simply put, if I experience something related to endometriosis, I can track it in Phendo," English explained.


"Say I experience a moment of pain. It's very sharp, and kind of pulling on my lower back, on the left. I would open Phendo, tap 'track this moment' and tap 'are you in pain now?'."

The treatment, for example, two paracetamol tablets, could also be recorded.

Deborah Bush of Endometriosis New Zealand partnered with the project after working in the field for more than 20 years.

The app and the data it would collect had enormous potential to help sufferers and medical professionals to better understand the disease.

Bush said she hoped better understanding would mean more women and teenagers were able to get on with their lives free from the pain of endometriosis.

"Twenty-seven per cent of [Kiwi] schoolgirls are not going to school most or every month because of period pain," she said.

"This is a public health issue we can no longer ignore."

To participate in the research and learn how to download Phendo, visit: