Meningiomas are mostly benign tumors, and many patients ignore them after realizing that they are benign tumors. In fact, meningiomas can directly cause local damage to brain tissue, affect cerebral blood circulation, block cerebrospinal fluid circulation pathways, and cause hydrocephalus or cerebral edema if left untreated, resulting in brain herniation and threatening patients’ lives. So, what are the specific hazards of meningioma? This article will introduce the common hazards of meningioma. Visual impairment: Visual field impairment is the most common symptom of saddle node meningioma, and almost all patients have visual acuity and visual field changes. 80% of patients have the first symptom, and visual impairment is slow and progressive, which can last for months or years. In the early stage, one side of the vision loss with temporal visual field defects, unilateral visual impairment accounted for 55%, and then the contralateral optic nerve and optic cross compression manifested as bilateral vision loss or bilateral visual field defects, bilateral visual impairment accounted for 45%, and finally can lead to blindness. Some patients are often first seen in the ophthalmology department. In addition, due to optic nerve and optic cross compression, primary atrophy of the optic disc often occurs in the fundus, which can be as high as 80%, and secondary fundus edema can also occur in late stages due to increased intracranial pressure. Increased intracranial pressure: Although meningioma is a benign tumor, with the growth of the tumor, meningioma will encroach on the limited space of the brain, which will cause increased intracranial pressure, and increased intracranial pressure will cause headache, vomiting, blurred vision, diplopia, dizziness, tinnitus, irritability, drowsiness, seizures and other symptoms. Increased intracranial pressure in meningioma not only has the above effects on patients, but also leads to rapid deterioration of the disease and life-threatening effects. Depending on the location of the tumor, proptosis, visual acuity, visual field, olfactory or auditory disorders and limb movement disorders can occur. If the tumor affects the olfactory tract, the sense of smell may be diminished or disappeared on one or both sides; if the frontal lobe is involved, it may cause drowsiness, memory loss, anxiety and other mental symptoms; if the cavernous sinus is compressed, it may cause articulatory nerve palsy and eye protrusion. Pituitary and hypothalamic dysfunction: endocrine dysfunction of pituitary gland and hypothalamic damage are rare, but when the tumor grows up and presses the pituitary gland, symptoms of hypopituitary dysfunction may occur, such as decreased libido, impotence or amenorrhea; when the hypothalamus is involved, polyuria, obesity and drowsiness may also appear.