<unk>  is a congenital or acquired narrowing of the<unk>  airway. It can be congenital, acquired, iatrogenic, or very rarely, idiopathic. It is defined as the narrowing of the portion of the airway that lies between the vocal cords and the lower part of the cricoid cartilage. In a normal infant, the<unk>  airway is 4.5-5.5 millimeters wide, while in a premature infant, the normal width is 3.5 millimeters.<unk>  is defined as a diameter of under 4 millimeters in an infant. Acquired cases are more common than congenital cases due to prolonged intubation being introduced in the 1960s. It is most frequently caused by certain medical procedures or external trauma, although infections and systemic diseases can also cause it.
Subglottic stenosis
Laryngotracheal stenosis
Laryngomalacia
Laryngopharyngeal reflux
Meatal stenosis
Tracheoinnominate fistula
Velopharyngeal insufficiency
Tracheoesophageal fistula