5-year-old baby fever back and forth again and again fever can be seen in the respiratory system (such as influenza), the digestive system (such as diarrhea disease) or the blood system (such as acute leukemia) and other diseases, the specific need to be based on the specific circumstances of the child to determine. 1. Respiratory system diseases: such as influenza virus infection caused by influenza, most have a history of epidemics, clinical recurrence of fever, part of the high fever, accompanied by aches and pains in the limbs, headache and other systemic symptoms, nasal congestion, runny nose, or coughing symptoms are often mild. 2. Digestive system diseases: such as infectious diarrhea disease, the clinic may appear the above phenomenon, accompanied by diarrhea, vomiting symptoms, dehydration can occur in severe cases. 3. Hematologic diseases: such as acute leukocytosis, repeated fever, often with variable fever, accompanied by skin and mucous membrane hemorrhages, anemia, bone pain and other symptoms, examination of lymph nodes and spleen enlargement, etc., improve the bone marrow puncture examination can assist in the diagnosis. 4. Other: such as Kawasaki disease, also known as mucocutaneous lymph node syndrome, can also appear repeatedly fever, often accompanied by rash, chapped lips, etc., part of the child perfect cardiac ultrasound can be seen coronary artery dilatation. 5-year-old baby fever back and forth again and again, need to actively seek medical attention, by the specialist physician comprehensive assessment to determine the cause of the disease.