There are many reasons why fever does not go down, bacterial or viral infections or dysfunction of the thermoregulatory center can cause fever that does not go down. 1. Bacterial and viral infections: the most common is influenza, after the flu, it will trigger the patient’s body to have a higher body temperature, resulting in the accumulation of heat in the body, which can not be discharged from the body, thus triggering the body to have a high fever phenomenon. 2. Dysfunction of the thermoregulation center: when the body is healthy, the body temperature is regulated by the thermoregulation center, while heat stroke, cerebral hemorrhage and so on will lead to dysfunction of the thermoregulation center, so that the energy exchange system in the body can not work properly, and can not cool down in time, which will cause fever not to go down. The above are only some of the common causes. Prolonged fever will cause brain damage, it is recommended to go to the hospital in time to find out the cause of fever in order to choose the standardized treatment according to the doctor’s advice.