Cystic dark areas found locally in the ovaries are often clinically caused by the following reasons. 1. pathological cysts. At present, the etiology of ovarian cysts is still unclear. When the diameter is greater than 5 cm, surgery must be given. For ovarian chocolate cysts, no matter how big the diameter is, as soon as they are found, it is recommended to give surgery as soon as possible. If the local cyst grows bigger and bigger, the consequences will be unimaginable if it ruptures. 2. Due to physiological ovarian cysts. This is often due to the formation of the corpus luteum in the ovary after ovulation, and luteal cysts can be seen as cystic dark areas locally in the ovary through ultrasound. The diameter is often not greater than 5cm, and will often disappear on its own or shrink significantly after menstruation, and can be treated clinically without treatment.