Nine-month-old babies with recurring fevers are usually associated with factors such as low immunity, infectious diseases and blood system disorders. 1. low immunity: if the nine-month-old baby immunity is low, it will be easier to get infected, which may be manifested as recurring fever. 2. Infectious diseases: if the nine-month-old baby is infected with viruses, bacteria, mycoplasma, parasites, etc., there are also cases of recurring fever. 3. blood system diseases: nine months baby fever back and forth may also be due to leukemia and other blood system diseases. Nine months baby fever recurring, there may be other reasons, it is recommended to go to the hospital, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.