Endometriosis is a condition in which the cells that form the endometrial lining of the uterus begin to develop outside the uterine cavity, mostly on the ovaries. This abnormal growth of the endometrial cells on the surface of the ovaries or any other organ can damage the function of that particular organ.
This condition happens in the availability of the hormone estrogen and hence, endometriosis is typically seen in pre-menopausal women. Endometriosis is in quite an aggressive form in post-menopausal women, and involves complete progesterone resistance. This condition is not very common and is estimated to occur in about 6 to 10% of women.
The reason of this gynecological medical problem is unknown. But it is thought to happen genetically. Endometriosis can be caused by retrograde menstruation, that is, the backflow of menstrual blood into the Fallopian tubules. Another cause can include immune dysfunction.