“Laryngo” refers to the larynx and “malacia” refers to a body tissue that is soft, so laryngomalacia is a developmental condition where the larynx doesn’t form correctly and ends up being soft and floppy.
Normally, the epiglottis, a flap of cartilage located just above the vocal cords, makes a firm arc over the airway.
It’s connected to the larynx by cartilaginous structures called aryepiglottic folds.
In children born with laryngomalacia, the aryepiglottic folds are shorter than normal, so they pull the normally arc-shaped epiglottis down into a distinctive omega shape.
Weak laryngeal muscle tone is thought to cause the condition, but the exact mechanism isn’t well understood.
The cartilaginous tissues are also softer than normal, so they flop into the airway.
That means that when the child breathes, that floppy structure gets sucked into the airway, causing stridor which is a high-pitched, whistling sound during breathing.
In some cases the obstruction of the airway can be so bad that it can make breathing difficult.