Recurrent coughing in babies may be due to recurrent respiratory infections and also needs to be considered as a cough caused by allergies. There are usually several reasons for this: 1. Poor respiratory barrier function: Babies have poor respiratory mucous membrane motility and are unable to remove invading germs. At the same time, their respiratory mucosa has a poor function of secreting antibodies, which cannot kill the germs that invade the respiratory tract, making them prone to respiratory infections. 2. Immune insufficiency: the antibodies carried by infants from their mothers are basically consumed after 6 months of age, which is a physiologically low immune period, making them prone to respiratory infections. 3. Underlying diseases: including congenital heart disease, respiratory system dysplasia, or malnutrition. 4, environmental factors: including air pollution, seasonal changes, etc. 5, other: such as the repeated stimulation of allergens.