In short
Endometriosis is often staged from 1 (minimal) to 4 (severe) based on what a surgeon sees during laparoscopy: how much there is, how deep, and how much scarring. Stage doesn’t match how much pain you have. It’s more relevant to fertility and planning surgery.
On this page
How endometriosis is staged
The most widely used system is the revised American Society for Reproductive Medicine (rASRM) classification. It’s based on findings during laparoscopy, and gives points for the location, size and depth of endometriosis, ovarian cysts and scar tissue (adhesions).
- Stage 1, minimal: a few small, superficial spots
- Stage 2, mild: more spots, some deeper
- Stage 3, moderate: many deeper deposits, small cysts on one or both ovaries (endometriomas), some adhesions
- Stage 4, severe: many deep deposits, large ovarian cysts, dense adhesions that can bind organs together
Stage doesn’t predict pain
This surprises many people. Studies have found that the stage of endometriosis doesn’t closely match how severe someone’s pain is. Someone with stage 1 can have severe, disabling pain, while someone with stage 4 may have few symptoms. Pain depends on where the endometriosis is, how deep it is, inflammation, nerve involvement, the pelvic floor muscles and how sensitised the nervous system has become.
Pain that stops you living your life isn’t normal.
Talk it through with an Australian doctor online. No referral needed.
What stage does tell you
- It helps surgeons describe and plan surgery
- It’s linked to fertility, with higher stages more likely to affect the ovaries and fallopian tubes
- It helps compare results in research
Other systems also exist, including ones that describe deep endometriosis in more detail.
Stage 4 endometriosis
Stage 4 means extensive disease, often with large endometriomas and dense adhesions. It can affect the bowel, bladder and fertility. Treatment is often surgery by a gynaecologist experienced in complex endometriosis, sometimes with a colorectal surgeon, along with hormonal treatment and pain management. Endometriosis is not considered life-threatening, though rare complications such as bowel obstruction need prompt treatment.
Can endometriosis get worse over time?
It can, but it doesn’t always. Some people’s endometriosis stays the same or improves. Hormonal treatment can reduce progression and recurrence.
Do I need to know my stage?
Not to start treatment. You can be diagnosed and treated based on symptoms and imaging. Staging only comes from surgery. See how endometriosis is diagnosed.
Next step: talk to a doctor
Answer a few quick questions and you’ll get an email about your eligibility. A consultation doesn’t guarantee any particular treatment.
References
- Vercellini P, Fedele L, Aimi G, et al. Association between endometriosis stage, lesion type, patient characteristics and severity of pelvic pain symptoms: a multivariate analysis of over 1000 patients. Hum Reprod. 2007;22(1):266-71.
- Becker CM, Bokor A, Heikinheimo O, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022;2022(2):hoac009.
- Zondervan KT, Becker CM, Missmer SA. Endometriosis. N Engl J Med. 2020;382(13):1244-1256.
- Zondervan KT, Becker CM, Koga K, et al. Endometriosis. Nat Rev Dis Primers. 2018;4(1):9.
This guide is general information, not medical advice. It doesn’t replace a consultation with a doctor who knows your history. In an emergency, call 000.