Infant’s nose whistling like phlegm, may be physiological phenomenon, hypertrophic rhinitis, acute upper respiratory tract infection and other causes. 1. Physiological phenomenon: the baby’s cartilage development is immature, the support ability is relatively poor, in the process of breathing, air circulation will be blocked, can be manifested as a huffing and puffing like phlegm. 2. Hypertrophic rhinitis: If the baby suffers from hypertrophic rhinitis, it can cause edema and congestion of the nasal mucosa, which can hinder the air circulation in the respiratory tract, and when breathing, the nose appears to be puffing like phlegm. 3. Acute upper respiratory tract infection: when the acute upper respiratory tract infection, can cause nasal congestion, runny nose and other symptoms, nasal air flow obstruction caused by nasal puffing. Parents are advised to take their babies to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to avoid delaying the condition.