The danger of widening of the septum lucidum is related to its cause. If it is caused by physiological development, it is usually harmless; if it is caused by hydrocephalus, it may appear dizziness, epilepsy and other hazards. 1. Widening of the septum is often caused by congenital development, which is generally harmless. If the patient has no symptoms, widening of the septum will not cause functional disorders, and no special clinical intervention can be carried out, and it is recommended to carry out clinical follow-up and regular review. 2. Partial widening of the septum may be caused by hydrocephalus, septal cysts, insufficient cerebral blood supply and other pathologic factors, and if the widening of the septum is more than 10mm, it may cause certain harm. Such as numbness, hemiplegia, epilepsy and other neurological dysfunctions; due to the widening of the septum pellucidum compression of the brain tissue, dizziness, headache, vomiting and other symptoms; in severe cases, cerebral hernia may occur, and even threaten life. It is recommended to go to a regular hospital for timely consultation, identify the cause and actively treat the widening of the septum pellucidum.