How many stages of endometriosis are there?

There are four stages of endometriosis in the most commonly used staging system (ASRM): stage I (minimal), stage II (mild), stage III (moderate), and stage IV (severe). This staging is based mainly on what’s seen at surgery—such as the location, depth, and extent of lesions, plus scar tissue (adhesions) and ovarian endometriomas.

An important nuance is that stage does not reliably predict how much pain you feel or how much the condition impacts daily life. Some people with “low-stage” disease have severe symptoms, and others with “high-stage” disease have surprisingly little pain. That’s why we also focus on disease subtypes—like superficial disease, deep infiltrating endometriosis, and endometriomas—because where endometriosis is and how it behaves often matters more than the stage label; if you’d like, you can reach out to our team to discuss how staging and subtypes apply to your symptoms and goals.