The nose of a 3-month-old child is not ventilated, there are several clinical possibilities, 1, congenital posterior nostril atresia, this child, especially when sucking milk, the symptoms of breath-holding, the symptoms of non-ventilation will be more obvious, the child may have breathing difficulties, face suffocating purple, suffocating blue and other performance. 2, some children may be cold and cold, rhinitis, bilateral inferior turbinate hypertrophy, nasal cavity blocked by a large amount of secretions The nasal cavity, resulting in the nose is not ventilated, clinically is the most common situation, this situation is generally doctor’s examination, can see bilateral inferior turbinate hypertrophy, nasal cavity a large number of secretions blocked. If the secretions are sucked clean, the patient’s nasal ventilation will improve significantly. 3, some children have the possibility of nasal foreign bodies, which is not very likely, the child’s nasal cavity is mistakenly stuffed with foreign bodies or choking when eating milk, milk, milk blockage in the nasal cavity can also lead to nasal non-ventilation.