A 4mm separation of the cervical canal is not serious and may be associated with fluid buildup in the cervical canal, cervical lacerations, cervical polyps, cervical fibroids, and so on. If a woman has cervical separation, she can be treated with anti-inflammatory medication and have an ultrasound to review the condition. If the cervical canal is still separated by 4mm, then hysteroscopic examination can be used to clarify the cause of cervical separation. If it is caused by the presence of cervical fluid, cervical polyps, cervical fibroids, you can do hysteroscopy, given to the appropriate drainage, surgical excision treatment, and after the operation need to be sent to the pathology of the excised tissues, in order to clarify the nature of the lesion. In addition, when a woman is menstruating due to the discharge of blood from the uterine cavity, the separation of the cervical canal will also be appropriately widened, subject to the results of the clean menstruation.