Three months baby fever is mostly due to bacterial infection, viral infection and other causes of sepsis caused, can improve the blood routine, calcitoninogen and other related tests to assist in the diagnosis, 3 months baby is mostly due to bacterial infections, can follow the doctor’s instructions on the cause of the treatment and symptomatic support i treatment. Three-month-old baby fever, mostly caused by sepsis, mostly due to bacterial infections, you can improve the blood routine, ultrasensitive C-reactive protein, calcitoninogen and other related tests to assist in the diagnosis, three-month-old baby due to the age of the small, immune function is not yet perfect to bacterial infections are more common, you can under the guidance of the doctor to be cefuzodoxime and other anti-infective treatment. If you consider B. pertussis infection, you can follow the doctor’s instructions to be azithromycin anti-infection treatment. In addition, some babies may have respiratory syncytial virus infection, generally self-limiting disease, clinical no specific drug treatment, mostly symptomatic supportive treatment, can be given to cardiac monitoring, oxygen and sputum suction and other treatments, such as fever resulting in increased water loss, can be given to the physical cooling, rehydration of symptomatic supportive treatment. It is recommended that if a 3-month-old baby has a fever, go to the pediatric outpatient clinic of the hospital in a timely manner, under the guidance of the doctor to be targeted treatment. Baby’s age, immature immune function, please parents attention, to avoid danger.