Choanal atresia

Choanal atresia is a congenital disorder in which a membranous tissue blocks the back of the nose (also called the choana) due to failure of recanalization during fetal development. Choanal atresia can be unilateral or bilateral, depending on whether one or both nasal passages are obstructed. This prevents the air from entering the nasal passages, resulting in symptoms like difficulty breathing and a constantly stuffy nose.