Asymptomatic fever in babies may be caused by infectious factors, such as viral infection, bacterial infection, etc. It may also be caused by non-infectious factors, such as malignant tumors. 1. Infectious factors: when pathogens (such as viruses, bacteria, fungi, parasites, mycoplasma, etc.) invade the body, asymptomatic fever may be triggered, and common diseases include tuberculosis, malaria, meningitis and so on. 2. Non-infectious factors: such as malignant tumors, heat stroke, etc., can also cause asymptomatic fever. 3. Other: there are also a few babies can be due to strenuous activities, the body surface temperature increases, leading parents to think that the baby fever, and not accompanied by other symptoms. Baby asymptomatic fever, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.