Endometriosis · the figures

89 months. That's the median, not the exception.

Endometriosis is often dismissed as rare or vague. The figures tell a different story: it is one of the most common gynecological disorders, with a diagnosis process that structurally takes years.

How common it is

Bigger than you think

89 months

median time between the onset of the symptoms and the diagnosis in Dutch research: more than 7 years.

400,000 to It is estimated that 500,000

women in the Netherlands have endometriosis: the Endometriosis Foundation itself consistently mentions 1 in 10 women.

~10.000

women visited the GP for endometriosis in 2022, possibly an underestimate due to how the diagnosis is registered.

That last figure shows the problem at a glance: if 10,000 women visit the GP per year compared to an estimated 400,000 to 500,000 with the condition, then the vast majority are not, not yet, or never visible. The NVOG now explicitly recognises the problem: at the beginning of 2025, the professional association launched its own platform with the explicit mission to shorten the diagnosis process from 7 to 1 year.
What is striking

The delay is in three phases

Research into where exactly the delay occurs shows that the patient waits a median of 7 months before going to the GP, the GP needs a median of 35 months to refer, and the gynecologist then again a median of 5 months before diagnosis. Women who wanted to have children received a diagnosis faster than women who came with pain. Gynecologists confirmed in the media in early 2024 that the average 7 years is still the practice, although several hospitals are now seeing an increase in referrals.

“From a few months to up to 30 years. That's how much time there can be between the first complaint and the diagnosis.”

Why it was missed is

It is not in the patient, but in the look

Menstrual pain is considered normal

Severe pain is often seen as something that is simply part of having a period, rather than a signal.

GPs underestimate the occurrence

Research confirms that GPs underestimate both the prevalence and the degree of delay.

Not a simple test

Only keyhole surgery makes the diagnosis with certainty. A normal gynecological examination or an ultrasound is often not enough.

What the numbers do not tell

What does and does not count

Yes counted

What is visible

  • Women who are ultimately diagnosed
  • Treatment results in specialized endometriosis centers
  • Direct healthcare costs of laparoscopy and hormone therapy
Not counted

What is invisible remains

  • Anyone who is still in the middle of the years-long process sits
  • Who has now come to see the pain as chronic and normal
  • Missed school days, working days and fertility opportunities due to the delay
Sources

Where these figures come from

Median 89 months, range up to 30 years
Thesis 'Diagnostic delay in endometriosis' by Moniek van der Zanden, Radboud University/Rhinestate, via Medical Contact. See medischcontact.nl.
On average still 7 years, confirmed in 2024/2025
NOS, gynecologists from UMC Groningen and Catharina Hospital about persistent diagnosis delays. See nos.nl. The NVOG launched Endometriosis Wiser in 2025 with the aim of shortening the process from 7 to 1 year. See nvog.nl.
1 in 10 women, 400,000 to 500,000 in the Netherlands
Endometriosis Foundation, the Dutch patient organization, information page compiled with the NVOG endometriosis working group. See endometriose.nl.
~10,000 GP visits in 2022, possible underestimate
NIVEL report on women-specific conditions, commissioned by ZonMw and the Ministry of Health, Welfare and Sport, with the explicit note that endometriosis falls under an ICPC subcode. See nivel.nl.
Delay divided among patient, GP and gynecologist
Zorgkrant.nl, summary of Van der Zanden's thesis. See zorgkrant.nl.

🏎 Need immediate help?

In case of immediate danger to yourself or someone else: call 112. Are you in distress or are you thinking about suicide? You can call or chat with 113 Suicide Prevention day and night via 0800-0113. Zorgfuik is not a crisis service and cannot solve acute requests for help, but we think it is important that you know where you can go.