About 14 per cent of Australian women, or one in seven, aged 44 to 49 have endometriosis, the latest research from the Australian Institute of Health and Welfare has revealed.
And the rate of hospitalisations for the condition has doubled among women aged 20 to 24 in the past decade.
"Endometriosis is a progressive chronic condition where tissue similar to the lining of the uterus grows in other parts of the body," AIHW spokesperson Katherine Faulks said.
"Endometriosis causes inflammation and scarring, which can lead to painful adhesions joining together pelvic organs that are normally separate.
"Women may experience pain, heavy menstrual bleeding, bleeding between periods, abdominal bloating, fatigue, anxiety, depression and reduced fertility, among other symptoms."
By age 31, 9.2 per cent of women born between 1989 and 1995 were diagnosed with endometriosis, compared with 6.9 per cent of women born between 1973 and 1978 at the same age, according to researchers from the University of Queensland.
"This increase may reflect increased awareness of endometriosis among the general public and health professionals, leading to increased diagnosis and/or reporting of diagnosis among women born more recently," Faulks said.
Diagnosis and management of endometriosis is complex, with an average of between six and eight years between the onset of symptoms and diagnosis.
There were 40,500 endometriosis-related hospitalisations in 2021–22 and endometriosis was the 20th most common reason for hospitalisation among those aged 15–44.
The rate of hospitalisation has almost doubled in the last 10 years from 160 hospitalisations per 100,000 females in 2011–12 to 310 hospitalisations per 100,000 females.
While hospitalisations in Australia are generally increasing over time, the growth of endometriosis-related hospitalisations was greater than that seen for all female hospitalisations between 2011–12 and 2021–22.
The greatest increase was seen among ages 20–24, with the rate doubling between 2011–12 and 2021–22 (from 330 to 660 hospitalisations per 100,000 females).
Endometriosis was among the leading causes of hospital admissions in this age group.
Endometriosis-related hospitalisations were more likely to be partly or fully funded by private health insurance than all hospitalisations for females, and around twice as likely to be self-funded as all hospitalisations for females.
The report also shows a lower rate of endometriosis-related hospitalisations among First Nations peoples, and people living in lower socioeconomic areas and remote areas of Australia.
But further work is needed to understand the impact of endometriosis on priority populations, particularly those who face barriers to accessing health care services.
Although the AIHW report uses the term "females" in its report, it also noted that endometriosis could also affect transgender, non-binary, and gender-diverse people assigned female at birth.