How are the stages of endometriosis determined?

Endometriosis is a condition where tissue similar to the lining inside the uterus grows outside of it. The stages of endometriosis are determined by how much tissue there is, where it is located, and how deeply it grows into organs.

1. Stage 1 (Minimal): There are only a few small growths or implants. They are usually shallow and not very deep.
2. Stage 2 (Mild): There are more implants than in stage 1, but they are still shallow.
3. Stage 3 (Moderate): There are many deep implants. There may also be small cysts on one or both ovaries and thin bands of scar tissue called adhesions.
4. Stage 4 (Severe): This is the most advanced stage. There are many deep implants, large cysts on one or both ovaries, and many dense adhesions.

Doctors use imaging tests like MRI, as mentioned in the ENDO_STAGE study, to help see where the tissue is and how much there is. Sometimes, doctors need to do surgery to look inside the body to determine the stage. This helps them decide the best treatment.