When a five-year-old baby has recurrent fever, the common causes are respiratory system diseases, digestive system diseases, neurological conditions, etc., as follows: 1. Respiratory system diseases: common respiratory system diseases in daily life, when the baby is cold or infected by some pathogens, forming upper or lower respiratory tract infections, recurrent fever can occur. It is best to take your child to the hospital for a detailed examination, combined with the appropriate blood tests, to clarify the specific cause of the disease, so that targeted treatment can be. At the same time, according to the temperature, give reasonable antipyretic treatment. 2. digestive system diseases: children with some pathogenic bacteria infection, resulting in the presence of some inflammatory factors such as viruses and bacteria in the gastrointestinal tract, will have recurrent fever, but also can be accompanied by nausea, vomiting, bloating, diarrhea and other gastrointestinal symptoms. 3. neurological diseases: with encephalitis or meningitis, in addition to repeated fever In addition to repeated fevers, children can also have headaches, nausea, vomiting and other symptoms. Therefore, when a child has recurrent fever, it is best for parents to take the baby to the hospital for a detailed examination to clarify the specific cause so that the cause can be addressed.