Endometriosis is a disease of the female reproductive system that is characterized by endometrial tissue — tissue lining the uterus — growing elsewhere. These abnormally implanted tissue deposits go through the same cycle as the normal endometrium, but cannot be shed and expelled. This leads to symptoms such as pain and infertility.

How is endometriosis staged?

According to the American Society for Reproductive Medicine (ASRM), up to 10 percent of all women have endometriosis. However, not all women with endometriosis experience the same symptoms, and symptom severity does not correlate with the extent of the disease. To classify the disease, physicians evaluate patients using a system of staging that takes into account the location, extent, and depth of the endometrial lesions, as well as the presence and severity of adhesions and the presence and size of ovarian endometriomas.

What are the stages? 

There are four stages of endometriosis: minimal, mild, moderate, or severe endometriosis.

Minimal endometriosis also called stage 1 endometriosis, and is characterized by isolated implants and no significant adhesions.

Mild endometriosis (stage 2) is characterized by superficial implants that measure less than 5 cm in diameter without significant adhesions.

Moderate endometriosis (stage 3) involves multiple deep implants, small cysts on one or both ovaries, and the presence of flimsy adhesions.

Severe endometriosis (stage 4) consists of multiple deep implants, large cysts on one or both ovaries, and thick adhesions.

Most patients are found to have stage 1 or stage 2 endometriosis. The staging is made during the same surgical procedure called a laparoscopy, which is used to confirm the diagnosis and treat the condition.


Endometriosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.