Hi Bryanna,
Endometriosis has been officially established as an autoimmune disease since at least 2012, when Eisenberg published "Is there an association between autoimmunity and endometriosis?" Although that article is not publicly available (I have access as a graduate student), I have found several that are available online for free so that you can see some of the research for yourself! Just google these titles and you should be able to read the PDF copy of the journal article.

-Treating endometriosis as an autoimmune disease (Nothnick 2001).

-Pathophysiology and Immune Dysfunction in Endometriosis (Ahn 2015).

-Potential Involvement of the Immune System in the Development of Endometriosis (Kyama 2003).

Endo is also listed here on the list of over 100 confirmed autoimmune diseases published by the American Autoimmune Related Diseases Association:
https://www.aarda.org/diseaselist/

Here's the problem that I've run into though - most providers haven't read these articles! Especially generic family doctors, ob-gyns, etc. they are NOT aware that in the last 15 years, a lot of research has been put into trying to find out whether endometriosis was officially an autoimmune disease and that research concluded that IT IS!

This is super important obviously because if they started to recognize endometriosis for what it is - an autoimmune disease - then that could potentially open up a lot of doors for treatment options that address the immune components of the disease rather than solely trying to suppress women's cycles using birth control or chemotherapy drugs like Lupron...
Anyways, as you can see, this is an issue I'm super passionate about so if anyone would like to message me or if you want to check out my blog, I've also written about it there and plan on expanding on it more in the future!
https://beginningwithendometriosis.wordpress.com/
Anna

Endometriosis is absolutely an auto-immune disorder. This is why woman with endometriosis also tend to have asthma, celiac, arthritis, hashimotos. Auto immune disorders tend to lead to other auto immune disordres.

Yea, I'm sure I have rheumatoid arthritis. I haven't been tested yet but I'm sure that I have it.

I believe it is and most endo sisters also have other auto-immune disorders.

I wonder that too but I think it has to be in our immune system and endo is in our reproductive system