Endometriosis and Hashimoto’s

The connection between endometriosis and thyroid autoimmune conditions

Sometimes people with an underactive thyroid experience endometriosis — a condition where the cells of uterine lining (endometrium) start growing outside of the uterus, including on the ovaries and inside the abdomen. This causes pain and inflammation, as well as putting reproductive health at risk (1).

People diagnosed with endometriosis usually have several different antibodies in their body — this is discovered through a blood test. The presence of antibodies indicates that endometriosis is likely an autoimmune disease (2,3).

There is not much known about the relationship between endometriosis and thyroid conditions, however the US Endometriosis Association reports that people diagnosed with endometriosis are six times more likely to have an underactive thyroid (4).

It’s known that thyroid hormones play a role in endometrial health and cell growth. In the context of pregnancy, this affects the possibility of embryo implantation, and the capability of the endometrium to produce some thyroid hormones independently of the thyroid gland (5–7).

Overlapping symptoms of endometriosis and an underactive thyroid:

  • Abdominal cramps

  • Painful bowel movement

  • Fatigue

  • Poor sleep quality

  • Feeling down

  • Difficulty becoming pregnant

Diagnosis and treatment

If you suspect you might have endometriosis, talk to your GP and OB-GYN. They may run a few tests to determine if you have endometriosis and they can help you decide on a treatment plan

Read more on our website, and download the BOOST Thyroid app to manage your thyroid health.


  1. Kennedy S, et al. ESHRE guideline for the diagnosis and treatment of endometriosis, 2005

  2. Gleicher N, et al. Is endometriosis an autoimmune disease? 1987

  3. Nothnick WB. Treating endometriosis as an autoimmune disease, 2001

  4. Sinaii N, et al. High rates of immune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis, 2002

  5. Taylor LJ, et al. The differential expression of oestrogen receptors, progesterone receptors, Bcl-2 and Ki67 in endometrial polyps, 2003

  6. Scoccia B, et al. In vitro fertilization pregnancy rates in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction disorders, 2012

  7. Aghajanova L, et al. Thyroid-stimulating hormone receptor and thyroid hormone receptors are involved in human endometrial physiology, 2011