Left adnexal cyst 25mm*19mm is mostly considered to be related to ovarian physiologic cysts and hydrosalpinx. 1. Ovarian physiological cysts: due to the cyclical changes of follicles in the ovary, there will be normal follicles, follicular cysts and corpus luteum cysts in the ovary during different menstrual periods, which are ovarian physiological cysts and do not require any special treatment, and can be rechecked by ultrasound after menstrual cleansing. 2. Tubal hydrosalpinx: for patients with a history of pelvic inflammatory disease and ectopic pregnancy, tubal hydrosalpinx may be formed due to adhesion of the umbilical end of the fallopian tube and increased exudation of local tissues as a result of local inflammatory stimulation. For patients with left adnexal cyst 25mm*19mm, it is recommended to go to the gynecology department of regular hospitals, complete the relevant examinations, clarify the cause of the disease and then actively treat it under the guidance of doctors.