Common classifications of pediatric cough include: 1. classification according to time: including the acute and chronic phases, where coughing >4 weeks is called chronic cough; 2. classification according to nature: including dry cough and wet cough. Dry cough refers to cough without sputum; wet cough refers to cough with sputum secretion; 3. Classification according to etiology: including infectious cough and non-infectious cough. Infectious cough is seen in bacteria, viruses, mycoplasma, chlamydia, fungi, etc.; non-infectious cough is related to physicochemical factors. The above classifications are clinically based mainly on the etiology of cough.