The main symptoms of congenital posterior nasal stenosis are nasal congestion, runny white mucus, olfactory disturbance and dyspnea. The severity of relief of the patient’s symptoms is related to the degree of atresia and age. Because newborns usually breathe only through the nose and have difficulty breathing through the mouth within 3 weeks of birth, children with congenital bilateral complete posterior nostril atresia present with severe respiratory distress, cyanosis and even asphyxia immediately after birth. In some children, although the symptoms are not as severe as those described above, the dyspnea worsens when feeding or when the mouth is closed, and cyanosis appears, resulting in refusal to feed. The dyspnea and cyanosis improve significantly or disappear when the child cries with open mouth. When the baby eats milk again or closes his mouth, the above symptoms appear again. Therefore, dyspnea often occurs in periodic episodes. The infant is prone to pneumonia and even death because of the nutritional impairment caused by the inconvenience of breastfeeding and the loss of filtration and humidification of the inhaled air due to the inability to suck. If the baby survives, it takes about 3 weeks for the newborn to become accustomed to breathing through the mouth, but he or she still holds his or her breath while breastfeeding. As the child grows older, the breath-holding or dyspnea symptoms tend to decrease. As a result, the child’s ability to think and communicate increases, and the child may complain of loss of smell or inability to blow the nose. In children with congenital unilateral posterior nostril atresia, shortness of breath may occur during feeding, but usually there are no obvious symptoms. However, there is one condition that needs to be taken into account, namely, infants with congenital unilateral posterior nostril atresia who are accustomed to breathing through the nostril on their side may experience sudden respiratory distress or asphyxia if the nostril on their side is occasionally blocked. Because of posterior nostril atresia, nasal secretions cannot drain from the posterior nostril into the pharynx, so the child shows white mucus flowing from the anterior nostril. In children with unilateral or incomplete posterior nostril atresia, the nasal cavity can still be ventilated and odor molecules can enter the nasal cavity and stimulate the olfactory nerve, so most of these children do not develop olfactory dysfunction. Loss of smell is seen in children with bilateral posterior nostril atresia. Children with congenital posterior nostril atresia are often associated with other deformities. Evans (1971) reported 65 cases of congenital posterior nostril atresia and 28 cases (43%) with other congenital malformations, including multiple congenital malformations (Charge’s syndrome), i.e. congenital iris defect, congenital heart disease, congenital posterior nostril atresia, growth arrest, genital hypoplasia, auricular malformation, etc. In addition, there may be other malformations, such as high arch of hard palate, flattened nose, congenital preauricular fistula, strabismus, iris palsy, maxillofacial osteogenesis imperfecta syndrome, external auditory atresia, ileal diverticulum, intestinal heterotaxy, urinary system malformation, polydactyly, etc. And there is a genetic predisposition.