In the early stages of pneumonia, children may cough up sputum or have a decreased appetite and fatigue, but in some cases, the onset of the disease is very rapid, with high fever and coughing up of pus and sputum without any antecedent symptoms. In the early stage of pneumonia, children may have atypical clinical symptoms, such as cough, sputum, or loss of appetite and fatigue, which may be mistaken for upper respiratory tract infection or acute bronchitis. However, the above symptoms may continue to worsen, and even obvious fever symptoms may appear. Pneumonia, however, may be acute in onset, and clinical symptoms may appear rapidly, with high fever and coughing up of pus and sputum in the early stages of the disease, which makes it relatively easy to diagnose at this time. Therefore, children with respiratory symptoms such as cough and sputum, if the clinical symptoms do not subside or worsen gradually, it is necessary to consult a doctor in time to find out whether it is pneumonia, and to treat the symptoms in time.