What Are Subglottic Cysts? 

Subglottic cysts are fluid-filled lesions in the lower part of the larynx, or subglottis, just below the vocal cords. They are a fairly common cause of airway blockage in children. There may be one or more cysts that block the airway below the larynx. Subglottic cysts are often treatable. They can cause total airway obstruction and even death if they are large enough and not treated right away.