To determine whether a small child is suffering from pneumonia, it is mainly through a combination of clinical symptoms and examinations. Pneumonia in small children is mostly due to lung infection, which causes a large amount of pus to appear in the alveoli, leading to difficulties in gas exchange and easy shortness of breath. Pneumonia can also be characterized by fever and chills, i.e. special fear of cold and even shivering. Children with pneumonia tend to cough in deeper areas, and sometimes hold their breath with a red face, etc. In case of pneumonia, if the total number of white blood cells increases and the proportion of neutrophils is also elevated, it is mostly caused by bacterial infection, but if the total number of white blood cells is normal or even low, it is mostly caused by viral infection. In the early stage of the disease, the X-ray film will show an increase in the texture of the lungs, and later on, the lungs will show flaky shadows. At the change of seasons, the possibility of pneumonia is higher for small children with weaker resistance. Once a child develops fever, cough, shortness of breath, etc., it is recommended to seek medical attention to rule out the possibility of pneumonia.