The severity of small airway and alveolar inflammation should be assessed in the context of the individual’s condition, as well as the infection, and should not be generalized, as it is generally less severe in young adults and more severe in older adults, infants and children. Inflammation of the airways and alveoli is commonly caused by bacterial infections and viral infections. 1. Bacterial infection: small airway and alveolar inflammation caused by bacterial infection is often caused by acute respiratory tract infections that are not treated in time. This can be cured with immediate treatment, clarification of the cause and symptomatic use of antibiotics, such as cephalosporin, amoxicillin and glucocorticoids. 2. Viral infections: viral infections of small airways and alveolar inflammation are mostly caused by serious illnesses and poor postoperative recovery, in addition to acute illnesses, such as upper respiratory tract infections, bronchitis and other diseases. It often occurs in patients who have been hospitalized and bedridden for a long time. For example, postoperative leukemia, diabetes, and patients who have been hospitalized in the ICU for a long time. At this time, not only conventional antiviral treatment is required, but also control of the main condition, which is complicated and more serious. In addition, young adults have better immunity, quicker recovery, less impact from small airways and alveolar inflammation, and more often less severe. On the other hand, the elderly and infants have low immunity and slow recovery, and airway and alveolar inflammation has a greater impact, and the condition is more serious if not treated in a timely manner. Therefore, it is necessary to consult a doctor in time and cooperate actively with the doctor’s treatment when the above symptoms occur.