Endometrosis is a condition that occurs when specialised tissue that normally line the inside of the uterus (the endometrium), become implanted outside the uterus. The uterus is the place where a baby grows when a woman is pregnant. This implantation most commonly occurs on the fallopian tubes, ovaries, bowels or the tissue lining the pelvis. Although rare, there have been reported cases of these cells being found in the lungs, liver and even the brain.
In endometriosis, displaced endometrial tissue continues to act as it normally would, that is, it thickens, breaks down and bleeds with each menstrual cycle. Because this displaced tissue has no way to exit the body, it becomes trapped wherever it has found itself.
Tissues surrounding it can become irritated, eventually developing scar tissue and adhesions (abnormal tissue that binds organs together and that can cause organ dislocation). Fallopian tubes, ovaries, the uterus, the bowels, and the bladder can be bound together in ways that cause pain — sometimes severe — especially during the period. In some cases, the condition is so severe that pain occurs on a daily basis, not just during menstrual periods. Many cases of endometriosis are asymptomatic and go unreported and unnoticed, so the exact percentage of women who experience these abnormal tissue growths is impossible to determine. Current estimates, though, suggests that 6-10% of women are affected. Endometriosis may occur at any time during the reproductive years, i.e. from the onset of menstruation to menopause but it is most commonly diagnosed between age 25-30.
Fertility problems are also associated with this condition.
The cause of endometriosis is unknown even after years of extensive scientific study.
What is known is that a variety of pathological issues may contribute, including:
Recent research shows that a common trait of pathological endometrial tissue is progesterone insensitivity, and an imbalance of estrogen receptors and growth factors, such as VEGF, an epidermal growth factor.