Some physiological ovarian cysts with a diameter of about 3 cm will disappear with the menstrual cycle, whereas cysts of larger size or pathological ovarian cysts will not disappear on their own. Physiologic cysts are usually small in size, within 3 cm in diameter, and are found to be simple, translucent, thin-walled cysts in the ovarian cortex under ultrasound detection, which gradually disappear with menstrual cycles. In contrast, pathological ovarian cysts can be larger than 5 cm in size and do not disappear with the menstrual cycle. Some ovarian cysts can grow rapidly within a short period of time and may be found to have ovarian masses, or solid echogenicity under ultrasound detection. Therefore, if a patient has an ovarian cyst of 5 cm or more and it persists for more than 3 months, it is pathological and surgery should be considered.