Ovarian cysts 4cm, if it is physiological cysts are generally not serious, if it is a pathological cysts need to do further diagnosis to determine whether it is serious or not. 1. Physiological cysts: If the ovarian cysts of women of childbearing age are less than 5cm, most of them are physiological cysts, which may be caused by the failure of follicles to be discharged in time, and generally do not affect the health of the body, and it is recommended that they be observed on a regular basis, and they will generally disappear on their own. 2. Pathological cysts: If the cysts do not disappear after review, but the patient has no other symptoms, most of them are benign tumors and can be left untreated; however, if you find that there are uncomfortable symptoms or ultrasound shows that the surrounding blood vessels are rich, then you need to further consult a doctor for examination and treatment, and surgical resection is needed when necessary. Patients with ovarian cysts are advised to seek timely medical attention, complete relevant examinations, and have the nature of the cysts confirmed by a professional doctor before intervening.