Delayed swallow reflex

Refers to when a person’s automatic swallow reflex—which normally kicks in when liquid or chewed food in the mouth reaches the base of the tongue—is delayed. Individuals with normal swallowing rarely notice or think about the action of their swallow reflex, but on occasion the reflex may startle a person and draw more attention to itself: for example, when a person sucks on a hard candy that inadvertently goes a little too far back in the mouth and—gulp!—it is involuntarily swallowed.

If a person’s swallow reflex is delayed, then food material may slip back to the base of the tongue and, before the swallow happens, drop down to fill the vallecula or even the pyriform sinuses. A delayed swallow reflex is of particular concern when swallowing liquids because, given their low viscosity, thin liquids can easily flow downward into the larynx and trachea (aspiration). Compare this disorder with absent swallow reflex.