Endometriosis

https://www.nhs.uk/conditions/endometriosis/

Symptoms

Impacts

Prevalence

I can't find any hard data on the prevalence of endometriosis globally but it's estimated to be in the range of 5-10% for women of reproductive age. ¹ ² ³ This rises to 30% to 50% in patients with infertility and/or pain.¹

The UK's Office for National Statistics (ONS) provides a more data-driven estimated minimum for diagnosed patients in England however, based on an analysis of 2011 UK census data linked to English Hospital Episode Statistics (HES).⁴ The bulletin states the percentage of women of reproductive age with a diagnosis of endometriosis is estimated to be 2%.

As noted in the bulletin⁴, this is likely an underestimate of the true prevalence of this condition, as many women will not have a diagnosis and the average age at diagnosis was 35 years. In other words, an entire generation of women are undiagnosed and missing from the data. BIPOC (1) and religiously orthodox populations are also far less likely to seek a diagnosis at all for various reasons (as noted in some of the studies, reports and web pages referenced below) and are also missing from the data. With that in mind I think it's fair to say that an estimate of 5% is probably accurate at a minimum and, when taking into account women who will never seek care for milder symptoms, 10% is entirely feasible.

Black, indigenous and other people of colour

Heritability

Whilst the etiology (cause) of endometriosis is unknown, it's believed around 50% is likely inherited via genes (from a person's parents).²

Diagnosis

Diagnosis typically takes a significant (and unacceptable) amount of time on average. Laparoscopic (aka keyhole) surgery is often required to obtain conclusive evidence (and in many countries this simply isn't available). Physical examination and ultrasound & MRI scans are often performed first and may be relied upon entirely where laparoscopic surgery is unavailable.

The WHO states the average time to diagnosis is 4 to 12 years.³
The UK's Endometriosis UK charity reports in 2026 that the average time to diagnosis in the UK is now 9 years and 4 months (based on survey data from 3075 respondents) and 11 years for those from 'ethnically diverse communities' (based on survey data from 351 respondents). This is addition to the average of 3½ years respondents took from first noticing symptoms to seeking medical assistance.⁵.

Diagnosis can be complex as symptoms can be similar to other conditions but this does not justify the delays many (if not most) patients endure. As is the case with many gynaecological and female-dominant conditions, patients are often assumed to be lying, 'making a fuss' or told they are too young to have health issues and their symptoms often minimised or dismissed.

Treatment

There is no cure for endometriosis. Treatment essentially involves minimising symptoms and is usually applied in the following sequence (with the first two often used together);

NSAIDs of increasing strength
Hormonal contraception (often changed until the most effective drug is identified)
Laparoscopic (keyhole) surgery to identify and remove endometriosis via electrosurgical heat treatment or excision
Rarely, laparotomy (open) surgery to remove endometriosis via electrosurgical heat treatment or excision

Repeat surgeries may be required.

Metadata

Created:

Last Updated: 2026-03-04

Endometriosis

Prevalence

Heritability

Diagnosis

Treatment

Further Reading

Metadata

References