Endometriosis stages and what they mean
60-second summary
Endometriosis is divided into four stages (I to IV) by the ASRM, based on how much tissue and scarring is seen during a keyhole surgery. The stage does not tell how much pain you feel, and it only partly predicts fertility. A tool called the Endometriosis Fertility Index (EFI) can help guide the next steps.
Endometriosis stages (ASRM)
| Stage 1 (minimal) | A few small surface spots | Mild |
|---|---|---|
| Stage 2 (mild) | More and deeper spots | Mild to moderate |
| Stage 3 (moderate) | Many spots, small chocolate cysts, some adhesions | Moderate |
| Stage 4 (severe) | Large cysts, dense adhesions, tubes or bowel stuck | Often needs IVF |
Stage describes how much and where — not how much pain you feel. Stage 1 can be very painful.
Source: KedVia original diagram · KedVia medical illustration team