choanal atresia choanal atresia, unilateral https://www.malacards.org/card/choanal_atresia_unilateral Unilateral choanal atresia is a, usually sporadic, congenital anomaly that is more commonly seen in females than in males (2:1), where the nose is blocked by bony or soft tissue formed during embryologic development on only one side (more commonly on the right side) and which is characterized by nasal obstruction and rhinorrhea, usually presenting at birth but that may go undetected until a respiratory infection aggravates the condition. icd11.foundation:1247369366 Orphanet:137917 UMLS:C5680630 MONDO:0015312 MEDGEN:1843076 GARD:0019889