A high fever will not cause brain damage if the fever is effectively reduced and the primary disease is treated appropriately. If the fever is not reduced in time, the body temperature continues to rise, and the primary disease is not treated effectively, it may cause brain damage. Persistent high fever can cause damage to the brain, mainly because high fever will lead to over-excitation of the cerebral cortex, which will lead to irritability, lethargy, convulsions and other neurological damage. If high fever is caused by encephalitis, meningitis and other diseases, it is also easy to affect the normal metabolism and function of brain cells, which may induce convulsions, cause febrile convulsions, and lead to brain cell function damage. Fever is a symptom of disease, there are many causes of fever, you need to go to the hospital, after clarifying the cause of the disease, to carry out targeted treatment, do not do it yourself, so as not to delay the condition.