Parents and friends are often overwhelmed and puzzled by the recurring fever in their children within a short period of time. Children are at the beginning of their lives, and all body functions are slowly developing, progressing and becoming perfect, including the immune system, which generally takes until about 6 years old to develop perfect immune function, so the period after the age of half a year is often a period when children are prone to infectious diseases, such as respiratory infections, intestinal infections, central nervous system infections and so on. But why do some children get better and others get sick repeatedly? There are some individual differences or differences in environmental factors. The same environment, the same disease, different children, different clinical manifestations, different severity of disease, and different degree of smooth treatment. Many parents ask why our children get sick. This is determined by two factors: one is the internal factor, which is the child’s own condition, including nutrition level, immune level, etc.; the second is the external factor, including environmental factors, exposure to pathogenic species and virulence strength, etc. When a child is malnourished, has a low immune level for a short period of time or has an immune deficiency, and is exposed to adverse environmental factors, his or her own immune system cannot clear the germs that invade the body in a timely manner, which eventually leads to the occurrence of diseases. If fever is accompanied by cough, sputum and shortness of breath, pneumonia should be considered. Consider soft tissue infection, cellulitis, etc. For different infectious diseases, according to the different types of infectious pathogens, we should choose the appropriate antiviral and antibiotic applications, and treat them with a full course of treatment to assist our own immune system to clear the infectious pathogens and achieve the purpose of disease cure. Some people may ask what is meant by a full course of treatment, and what will be the problem if there is no full course of medication? Here is an example of an 8-year-old child who had recurrent tonsillar suppuration in the last 2 months. After asking the medical history, we found that the child often had fever and tonsillar suppuration again within a short period of time after each treatment. There was also a 5-year-old child from Xinxiang who had recurrent fever within 2 months, and was diagnosed with septic meningitis after coming to us for a complete examination, and after asking about the medical history, we found that the child did consider intracranial infection during the initial local treatment, and tended to have viral encephalitis. The disease was cured clinically with the application of advanced antibiotics, which induced bacterial resistance and increased the difficulty of subsequent treatment. From these two examples, we can see that it is necessary to have a full course of antibiotics for infectious diseases, especially bacterial infections. The use of antibiotics must be regular and, in cases where they must be used, regulated to help the disease heal successfully. In the face of infectious diseases, if the treatment does not go well, or regular treatment premise, but still the disease is repeated, delayed, or each time very serious, we need to be alert to the possibility of immunodeficiency diseases, such as selective IgA deficiency, congenital absence of gammaglobulinemia, congenital granulocyte deficiency, complement deficiency, etc., need to further improve the relevant tests to clarify, if necessary, early intervention, treatment Reduce the probability of occurrence of infectious diseases. Finally, we do not need to be overly anxious when facing infectious diseases. In most cases, the disease can be overcome with appropriate treatment, and the child will experience an accelerated growth of immune function and eventually healthy growth after experiencing one disease blow after another.