What is endometriosis?

Endometriosis is a common but still largely underestimated disease that affects about 10% of women of childbearing age. It is a benign and complex gynecological condition that can begin with the first menstrual period and its symptoms do not stop until the menopause.

Il s’agit d’une maladie au cours de laquelle des cellules semblables à  l’«endomètre », s’implantent en dehors de leur place habituelle dans l’utérus, soit dans le myomètre (muscle utérin, on parle alors d’adenomyosis) or out of the uterus (one speaks then about lesions or or endometriosis sites). These cells are endometriosis foci and are most often located in the lower abdomen (on the peritoneum, in the ovaries, intestine or bladder) or, more rarely, on other organs (diaphragm, pleura, lungs).

Like the endometrium, endometriosis foci react cyclically and bleed because they are under the hormonal influence of the menstrual cycle. For this reason they are referred to as hormone-dependent diseases. In contrast to the menstrual blood that flows into the vagina with each cycle, blood from endometriosis sites cannot flow outwards, so it accumulates in the abdominal cavity. The surrounding tissue also becomes inflamed. The irritated tissue then progresses to scarring, which can lead to adhesions. Following cyclic bleeding, the endometriosis sites migrate and are grafted onto the neighbouring organs (intestine, ureter, bladder).

Not only does endometriosis disrupt the physical well-beingbut it can also have consequences psychological, social and affect the relationship with the partner..

Endometriosis lesions can be of three types:

  • superficial and affect the peritoneum
  • adnexal and therefore touch the ovaries and tubes.
  • deep (beyond 5mm from the peritoneum) and infiltrate mainly the utero-sacral ligaments (which connect the uterus to the sacrum at the back, more frequent on the left), the rectum and the bladder.

Remember that there is no correlation between the intensity of the pain or the type of endometriosis and that superficial endometriosis can be very painful.


What causes endometriosis?

The causes of endometriosis are multifactorial. Indeed, there are several theories to account for endometriosis. However, genetic factors and toxic substances in the environment predispose to its occurrence.

The "retrograde menstruation" theory (of regurgitation and implantation)

This is the most important theory. During menstruation, most of the blood usually flows from the uterine cavity into the vagina and out. However, in most women, some of the menstrual fluid also drains into the abdominal cavity up through the fallopian tubes. This blood contains viable endometrial cells. These cells then attach themselves to the surface of the organs of the pelvis and abdomen (peritoneum), and then grow under the effect of chronic inflammation and create endometriosis lesions. However, it should be noted that this tubal reflux is physiological (i.e. normal) in almost 90% of cases: endometrial cells that are transplanted elsewhere are usually destroyed by the immune system. Other factors are therefore necessary for the development of endometriotic disease, the main ones being: alteration of the immune system, genetic predispositions, endocrine disruptors.

Metastatic theory

The dissemination of endometrial cells by blood or lymphatic route, allows to account for very rare cases of localization of endometriosis outside the abdominal cavity (lungs, brain, bones etc).

Stem Cell Theory

It is based on the hypothesis of a neonatal menstrual reflux. These dormant endometrial stem cells, which implant and survive permanently, could explain the early onset of the disease in some patients.

Source : Nous remercions la clinique Mons Endométriose d’avoir mis à notre disposition ces informations médicales.