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Causes of endometrial hyperplasia
Last reviewed: 05.07.2025
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For the correct treatment of uterine diseases associated with pathological proliferation of stromal and glandular components of the mucous membrane of its cavity, it is necessary to establish the causes of endometrial hyperplasia and its nature.
Depending on the characteristics of structural changes during hyperplastic processes in the tissues of the inner lining of the uterus, gynecologists distinguish glandular, cystic (glandular-cystic) and polypoid hyperplasia. What causes the development of this common pathology?
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Causes of glandular hyperplasia of the endometrium
Hyperplasia is defined as glandular when the epithelial cells of the tubular glands present in the thickness of the uterine mucosa grow abnormally. The main causes of glandular hyperplasia of the endometrium (as well as other structural forms of this pathology) are rooted in disturbances in the production of female sex hormones estrogen and progesterone or in the absence of their physiological balance.
The synthesis of sex hormones in the female body occurs cyclically, and also cyclically - under the influence of these steroids - three-phase morphological transformations of the endometrium occur monthly: proliferation (phase of folliculin action), secretion (phase of lutein action) and desquamation (rejection). They affect the functional layer of the endometrium (consisting of the superficial and spongy sublayers with glands and stroma) that is subject to rejection, which during the middle stage of the cycle thickens almost five times. The endometrium is thickest before the onset of menstruation, and the thinnest - immediately after its end.
The effect of estrogen, which stimulates the proliferation of cells of all endometrial structures, is neutralized by progesterone, which in the second half of the cycle suppresses the growth of the mucous membrane of the uterine cavity - so that during the next preparation for the implantation of the embryo into the epithelium of the uterus, it turns into the so-called decidual tissue, necessary for the further development of the embryo.
And the main reason for endometrial hyperplasia is an excess of estrogen and a lack of progesterone to counteract it. After all, these hormones control the monthly process of preparing the uterus for pregnancy.
Causes of glandular cystic hyperplasia of the endometrium
The causes of glandular-cystic endometrial hyperplasia are not much different from the etiology of glandular hyperplasia: the only difference is in the structure. And this difference occurs due to the appearance of cysts in the lower layers of the mucous membrane of the uterine cavity - small capsules limited by a shell with various contents, most often liquid. Cysts can also form directly in the endometrial glands. This disrupts the normal blood supply to the tissues, squeezing the vessels, which, against the background of estrogen-progesterone imbalance, aggravates its abnormal growth.
In addition, the development of all forms of hyperplastic processes in the uterine mucosa may be associated with chronic diseases (diabetes mellitus, polycystic ovary disease, hereditary non-polyposis colorectal cancer); inflammatory diseases (endometriosis, endocervicosis, oophoritis, salpingitis, adnexitis); neoplasms in the uterus (adenomyosis, myoma, fibromyoma, leiomyoma, estrogen-secreting ovarian tumors), as well as infection with the herpes virus and papillomavirus.
Obesity makes a significant "contribution" to the development of this pathology, since "excess" estrogen is stored in adipose tissue. For this reason, endometrial hyperplasia is diagnosed much more often in women with excess body weight.
As gynecological practice shows, women who have menstrual cycle disorders are at greater risk of developing endometrial hyperplasia. Also, the process of pathological proliferation of cells of the mucous membrane of the uterine cavity and the tendency to form cysts can be genetically determined and inherited.
Causes of polypoid endometrial hyperplasia
The causes of polypoid endometrial hyperplasia, which gynecologists call focal, are associated with all of the above factors and, in particular, with progesterone deficiency.
In this form of the disease, the hyperplastic process occurring in the endometrial tissues is accompanied by the formation of abnormal formations in the form of polyps - single or multiple nodes protruding above the mucosal surface on a "stalk" of varying height and thickness. As gynecologists note, this most often occurs in premenopausal women and for the same reason as endometrial hyperplasia itself. Polyps can consist of connective or glandular tissue cells, endometrial glands, and fibrous fiber particles.
In younger women, the development of polypoid endometrial hyperplasia is facilitated by mechanical abortions, other methods of terminating unwanted pregnancies, spontaneous termination (miscarriage), curettage (scraping) of the uterine cavity, and long-term contraception using an intrauterine device.
Thus, after childbirth or abortion, polyps in the uterus can form from placental particles (placental polyps). Histological examination of samples taken during biopsy may reveal atypical cells, indicating an increased risk of malignancy of polypous formations.
As you can see, the causes of endometrial hyperplasia are serious, and a process that is not detected in time - without treatment - can lead to equally serious consequences. Therefore, with any disruption of the menstrual cycle, with "incomprehensible" vaginal bloody discharge (or bleeding), you need to go to the gynecologist.