Endometriosis is a medical condition that primarily affects women during their reproductive years. It is characterized by the presence of endometrial tissue, which normally lines the uterus, in other parts of the body. This misplaced tissue goes through the same cyclical changes as the uterine lining, resulting in various symptoms and complications.
The endometrium is the innermost lining layer of the uterus, essential for female reproductive health. The endometrium is primarily composed of two main components:
Throughout the menstrual cycle, the endometrium undergoes significant changes influenced by hormones—primarily estrogen and progesterone—secreted by the ovaries. These hormones regulate the thickening, maintenance, and eventual shedding of the endometrial layer:
The health and integrity of the endometrium are vital for fertility. Disorders such as endometriosis, where endometrial-like tissue grows outside the uterus, or endometrial hyperplasia, characterized by an excessively thickened endometrial layer, can significantly impact a woman's reproductive and overall health.
Endometriosis is a condition where endometrial tissue is found outside the uterus or in inappropriate areas within the uterus. This misplaced endometrial tissue is referred to as ectopic endometrium. The condition is chronic, meaning it persists for a long time or constantly recurs.
Endometriosis can be classified into two types:
Internal endometriosis (or adenomyosis): This occurs when the ectopic endometrium is located within the myometrium, the middle layer of the uterus.
External endometriosis: This happens when the ectopic endometrium is found outside the uterus, such as on the ovaries, rectum, vagina, fallopian tubes, bladder, and even outside the pelvic region like the abdomen, kidneys, and lungs. External endometriosis is more common than internal endometriosis.
Endometriosis can affect women of any age, but it is more prevalent among women aged between 30 and 40 years. According to several studies, endometriosis affects 6-11% of the general female population. It is significantly more common among women who experience infertility and chronic pelvic pain.
The exact cause of endometriosis remains unclear, but several theories have been proposed to explain its onset:
Retrograde menstruation theory: This suggests that endometrial cells shed during menstruation flow backward through the fallopian tubes into the abdominal cavity, where they implant and form "endometriotic islands."
Dissemination via lymphatic and blood routes theory: This proposes that endometrial cells can reach other organs via the lymphatic system or the bloodstream.
Metaplastic theory: This postulates that cells of the peritoneum transform into endometrial cells due to unknown causes.
Hormonal theory: This theory suggests that estrogen activity during puberty induces the transformation of certain cells into endometrial cells.
Genetic predisposition theory: This believes that endometriosis may be a hereditary condition.
Iatrogenic implantation theory: This theory suggests that endometrial tissue can implant on surgical scars following procedures like cesarean sections or hysterectomies.
Endoperitoneal immune alteration theory: This proposes that a genetic mutation-induced anomaly in the immune system allows endometrial cells to survive and multiply in the abdominal cavity.
Several factors may increase the risk of developing endometriosis, including nulliparity (never having given birth), early onset of menstruation, late menopause, short menstrual cycles, prolonged menstruation, high levels of estrogen, heavy alcohol consumption, family history of endometriosis, conditions that prevent the normal passage of menstrual flow, and the presence of uterine anomalies.
The symptoms of endometriosis can range from none to severe and may include recurrent pelvic pain, vulvodynia (chronic vulvar pain), dysmenorrhea (painful menstruation), dyspareunia (pain during sexual intercourse), and heavy menstrual bleeding.
Endometriosis can lead to complications such as the formation of endometriotic cysts and adhesions, infertility, and an increased risk of ovarian cancer if the ovaries are affected.
Diagnosing endometriosis can be challenging due to the non-specific nature of its symptoms. The diagnosis process typically involves a collection of symptoms, evaluation of the clinical history, physical examination, gynecological examination, imaging diagnostics (like transvaginal or transrectal ultrasound, magnetic resonance imaging, CT scan), and sometimes a minimally invasive surgical procedure like laparoscopy.
The treatment of endometriosis is based on the severity of symptoms, the extent of the disease, and the patient’s future fertility plans. The treatment strategies are primarily divided into conservative and surgical approaches:
Physicians typically start with conservative treatments and consider surgery only if symptoms persist or worsen despite medical management.
The prognosis of endometriosis depends on various factors, including the extent of the disease and the patient's age. Although treatments may not be equally effective for all patients, those that are successful can significantly improve symptoms and restore fertility in many women of childbearing age.