The specific reasons why babies often have runny nose are as follows: 1. Babies have poor immune function or have cold symptoms due to improper parental care, so they often have runny nose. 2. Babies often have runny nose when they are not thoroughly treated for nasal inflammation after a cold, forming rhinitis or sinusitis, etc. They need to be given drugs for rhinitis under the guidance of an ENT doctor. If your baby is allergic or in the autumn and winter when the cold and heat alternate, there are often air irritation or allergic reactions to form a runny nose, in addition to avoiding cold and heat, air irritation, but also to avoid oral intake, contact with food or air dust that can easily trigger allergies in babies, combined with oral anti-allergy drugs for treatment when necessary.