More research is needed to truly understand how fast endometriosis grows. Here’s what we do know.

“The growth rate of endometriosis varies dramatically between individuals,” says Hugh Taylor MD, OB-GYN, a Yale School of Medicine expert who specializes in endometriosis and fibroids.

Typically, endometriosis grows fastest when you’re most fertile. In people assigned female at birth, this occurs during the late teenage years into the late 20s. Fertility usually starts to decline after age 30.

“Endometrial growth often slows as fertility drops in an individual’s 40s,” explains Taylor.

There’s very little research documenting how fast endometriosis grows, says Mary Jane Minkin, MD, OB-GYN, clinical professor of obstetrics, gynecology, and reproductive sciences at Yale University School of Medicine.

“The only real way to document growth would be to look during a laparoscopy, and no one does serial laparoscopies to observe endometriosis,” adds Minkin.

Experts typically use one of the following classification systems to diagnose the stage of endometriosis:

  • American Society for Reproductive Medicine (rASRM)
  • Endometriosis fertility index (EFI)
  • American Association of Gynecologic Laparoscopists (AAGL)

The rASRM system is the most common metric for classification. It has four different stages.

Each stage is associated with a particular numeric range, which is determined by several factors including the location, depth, and extent of endometrial-like growths and adhesions.

rASRM StageAlternative nameScoreManifestations of the endometriosis
Stage 1minimal1–5 pointsFew superficial growths
Stage 2mild6–15 pointsdeeper growths
Stage 3moderate16–40 pointsmany deep growths, small cyst(s) on the ovary, some presence of adhesions
Stage 4severemore than 40 pointsmany deep growths, large cyst(s) on the ovary, many deep adhesions

Yes, it has three main limitations.

First, your individual level of pain doesn’t influence the ultimate stage or classification given.

Someone who receives a stage 1 or stage 2 endometriosis diagnosis, for example, could have near-debilitating pain, while someone who receives a stage 4 diagnosis may not experience pain at all.

“Because pain isn’t related to stage, the staging isn’t helpful to predict symptoms or recurrence,” says Taylor.

The system also doesn’t take into account whether the disease has impacted your overall fertility.

Finally, the classifications aren’t particularly detailed. That means different clinicians could assess the same case of endometriosis and diagnose it as two different stages.

No. None of the classification systems are considered the gold standard.

The ENZIAN classification was developed to help clinicians classify deep infiltrating endometriosis. As such, this system can be useful for clinicians who are considering surgical intervention for the disease.

The EFI was developed to predict fertility outcomes in people who have already undergone surgery for endometriosis.

Developed in 2021, the AAGL classification is the newest. Researchers investigating the efficacy of this system found that it ”reliably discriminates surgical complexity levels better than the ASRM staging system.”

However, they add that the “AAGL severity stage correlates comparably with pain and infertility symptoms with the ASRM stage.”

But the rASRM system isn’t great at measuring pain or fertility. So, the AAGL system is still a far cry from being the all-inclusive staging system that many clinicians have been hoping for.

Endometriosis is usually diagnosed through a surgical procedure called a laparoscopy.

Your surgeon will make a small incision in your abdomen so they can insert a tiny tube with a camera (laparoscope). If they see any unusual growths or adhesions, they’ll take a small sample (biopsy) for further testing.

Many healthcare professionals advocate for a way to diagnose endometriosis without requiring such invasive intervention.

If clinicians could diagnose endometriosis from symptoms alone, “it would lead to earlier diagnosis and treatment, which could prevent progression of the disease,” says Taylor.

Can the stage at diagnosis affect the overall rate of growth?

According to Taylor, “There’s no clear relationship between stage and growth rate.” However, the earlier a diagnosis is made, the better. There are a variety of treatment options that can help people manage their pain as well as slow the progression of the disease, he says.

Some of these treatment options include:

  • pain medication
  • hormone therapy
  • surgery

If you’re experiencing any symptoms commonly associated with endometriosis, you should consult a healthcare professional.

And remember: Pain isn’t the only symptom of endometriosis, nor is it a symptom everyone experiences.

“Some people develop horrible endometriosis and have absolutely no pain whatsoever — they can have stage 4 disease spread everywhere and not know it,” explains Minkin.

Other common endometriosis symptoms include:

The rate at which endometriosis grows varies with each person. As such, there’s no way to predict how fast the disease will grow in any one person with the condition.

Gabrielle Kassel (she/her) is a queer sex educator and wellness journalist who is committed to helping people feel the best they can in their bodies. In addition to Healthline, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.