Endometriosis is a condition in which the cells that form the endometrial lining of the uterus, start developing 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 impair the function of that particular organ.
This condition occurs in the availability of hormone estrogen and hence, endometriosis is typically seen in pre-menopausal women. Although in post-menopausal women, endometriosis is in quite an aggressive form and involves complete progesterone resistance. This condition is quite rare and is estimated to occur in about 6 to 10% of women.