Gynecological examination ultrasound uterine adnexa found in the ovary fluid dark area, may be ovarian cysts, may also be follicles, ovarian cysts of different specific categories and nature, the cause will be very different. If it is a physiologic corpus luteum cyst, it is formed due to the accumulation of fluid in the ovarian capsule after the egg has been discharged. As long as there is no rupture of the corpus luteum cyst in the ovary, there is no need to do any treatment or therapy, and the cyst will disappear naturally after the onset of menstruation. If it is a common ovarian cyst, due to the high level of estrogen and progesterone stimulation in the body, it may shrink after menstruation, but will not disappear naturally. If an ovarian chocolate cyst is considered after examination, it is mostly due to endometriosis formed when the endometrium of the uterus is ectopic to the ovary.