Endometriosis is not caused by high levels of estrogen; its cause is not yet clear, and there are currently three theories about its pathogenesis, namely, implantation, epithelial chemotaxis in the body cavity, and induction. Although estrogen is not the cause of the disease, estrogen can promote the development of the disease.
1. Cultivation theory: Reverse flow of menstrual blood or transfer of endometrium to distant places through lymph and veins, or artificially bringing the endometrium to the incision site during caesarean section, etc., can cause the endometrium to be cultivated outside the uterine cavity, thus leading to endometriosis.
2. Epithelial chemotaxis theory, under the influence of ovarian hormone or after the stimulation of chronic inflammation, the epithelium on the surface of the ovary and the pelvic peritoneum may be activated and transformed into endometrioid tissue, thus leading to endometriosis.
3. Induction theory, undifferentiated peritoneal tissue is induced by endogenous biochemical factors to transform further into endometrial tissue, and the implanted endometrium may release chemicals to induce the formation of endometriotic tissue from undifferentiated mesenchyme.
Endometriosis is a hormone-dependent disease. Although estrogen is not the cause of endometriosis, the ectopic endometrium will proliferate periodically under the continuous influence of estrogen and may invade and metastasize to distant places. Therefore, exogenous estrogen supplementation is not allowed in endometriosis, or it will promote the development of the disease.