There are several obvious factors:
(1) normal ovarian cycle, only one mature follicle, which in the growth of follicles are in a shrinking process of maturation and atresia. May be due to pituitary gonadotropin in the follicle-stimulating hormone follicle-stimulating hormone and had even luteinizing hormone out of balance, as well as mature follicle does not ovulate and continuing degradation of incomplete follicular growth or atresia, granulosa cells continue to secrete fluid and form cysts.
(2) because of various conditions caused by congestion state of the ovary, such as chronic pelvic inflammatory disease, ovarian sag, resulting in ovarian blood supply obstacles to the thickened tunica albuginea, resulting in mature follicle does not rupture of ovulation, endocrine bubble formed by fluid retention cyst .
(3) follicular film for some reason, suddenly burst blood vessels, the formation of blood into the follicle cavity follicles hematoma, hematoma gradually absorbed, the blood cell components melt away, the liquid formed by an increase in retention cyst.