Endometriosis is a benign condition, in other words non-cancerous, but can be very disabling with a significant impact on quality of life. It can affect any woman of childbearing age and involves the implantation, outside the uterus, of the endometrium, which renews itself every month to bring about menstruation, more commonly called periods.

LUNA explains the essence of this condition, which affects between 10% and 15% of all women of childbearing age worldwide.

Understanding the mechanism of endometriosis

Long ignored, the  physiopathology of endometriosis is still little known or understood. Its diagnosis period is long: from 6 to 12 years on average, which deprives patients of appropriate care and changes their quality of life.

LUNA Mémo : The Menstrual Cycle

The menstrual cycle is a physiological and natural process, beginning at adolescence and lasting until menopause. During menstruation, the uterus contracts and drives the endometrium cells into the vagina, through the neck of the uterus: this is the normal phenomenon of menstruation.

During your period, some of your blood is discharged into your fallopian tubes, outside the uterus, and moves up to disperse into your abdominopelvic cavity (abdomen), not into your vagina. This phenomenon is experienced by all women as part of their menstrual cycle, whether affected by endometriosis or not.

This blood, which corresponds to endometrial cells (fragments of the endometrium) is then destroyed within a few days by the immune system and disappears naturally.

If you are suffering from endometriosis:

1. It has been scientifically shown that your endometrium is pathological, that is, different to that of women who do not have endometriosis.

This means that while all women have periods, your endometrium has unique aspects which help explain your endometriosis.

As your endometrium is different (more resistant to the immune system), the endometrial cells (fragments of the endometrium) discharged through the fallopian tubes to the abdomen will not be destroyed and can be grafted, implanted onto organs around the uterus: your ovaries, fallopian tubes, intestines, bladder, ureter.

However, your endometrium, even in an abnormal anatomical situation, is still affected by hormonal stimulation during different periods of your menstrual cycle, as it would be for any woman not suffering from endometriosis.

You will therefore experience heavy cyclic bleeding, or bleeding every month during your period, from the organ where your endometrium has implanted.

This recurrent heavy bleeding explains, depending on the location of the implantation, the development of endometriotic ovarian cysts (endometriomas), pelvic pain and peri-menstrual digestive and/or urinary symptoms, in other words in the days preceding menstruation and/or during your period.

2. It is also scientifically proven that your immune profile has changed

This second dysfunction, tied to the fact that your endometrium is pathological, helps explain why the endometrial cells, after menstrual reflux, aren’t destroyed by your immune system as is the case for most women.

These immune disturbances explain the very frequent association of endometriosis with many conditions where the immune system is heavily implicated: allergies, dysthyroid, lupus, inflammatory bowel diseases (Crohn’s disease, ulcerative colitis), scleroderma, migraines,…

What are the characteristics of endometriosis ?

Endometriosis is a condition that is:

dependant on hormones (or hormone-dependant): the painful symptoms are related to the menstrual cycle, which explains the efficiency of hormonal treatment that, by blocking ovulation and periods, helps relieve patients.

inflammatory: the regurgitation of blood in the abdominopelvic cavity during menstruation is an “aggression” that is responsible for inflammation, a source of pain that can be very intense during periods. This inflammation can be relieved by pain killers and/or by blocking menstruation by prescribing hormonal treatments.

neurological: endometriotic cells can penetrate the nerves, thereby contributing to pain felt by patients.

heterogeneous, and can therefore take different forms:

Anatomically there are three phenotypes, that is, three clinical presentations of endometriosis that may, or may not, be connected:

  • Superficial endometriosis, when the implants remain superficial on the surface of the peritoneum (tissue that lines the entire abdominopelvic cavity) and/or ovaries
  • Ovarian endometriosis or endometriotic cysts (endometriomas), when after successive heavy bleeding every month the lesions create a cyst in the ovary
  • Deep endometriosis when the lesions penetrate the abdominopelvic organs (bladder, ureter, intestine, vagina, …).

Multifocal, that means, the lesions are rarely isolated:  these three types of endometrioses (superficial, ovarian and deep), can be associated in the same patient, and the nodules of deep endometriosis are often multiple: for example, you can suffer from both vaginal and rectal endometriosis simultaneously.

What are the consequences of the endometriosis ?

The two main symptoms of endometriosis are pain and infertility.

Pain can come in different forms, sometimes related to:

  • Dysmenorrhoea, which is cyclic pain during your period
  • Dyspareunia, pain during sexual intercourse, which can have a huge impact on a patient’s sexuality
  • Chronic pain, that is, not periodically connected to the menstrual cycle
  • Signs, mainly digestive and/or urinary, repetitive, before and during the menstruation period, depending on where the lesions are located.

Infertility, in other words having difficulty getting pregnant, can be defined in two ways:

  • Primary, if you have never been pregnant;
  • Secondary, if you have already been pregnant, at least once, regardless of the course of that pregnancy: delivery (at term or premature; naturally or by caesarean), miscarriage, ectopic pregnancy, …

The impact of endometriosis on the quality of life of patients, both personally, maritally and professionally, is considerable. Long unknown, and even ignored, endometriosis is today, because of the disorders it causes and the very high cost of its diagnosis and treatment, considered a real public health problem.

 LUNA helps you :

LunaEndoScore is a diagnostic tool that, by calculating a risk score, determines your probability of being affected by endometriosis from your responses to a questionnaire.

Intented use :

LunaEndoScore aims to help detect endometriosis by calculating a risk score that determines the probability of being affected by endometriosis from users’ responses to a questionnaire.


Co-authored and scientifically validated by Dr Jean-Philippe Estrade,

Gynecological surgeon and expert in endometriosis at the Clairval Private Hospital and the Bouchard Clinic, in Marseille.


See also : LUNA Explains : Are My Periods Normal Or Not ?