What does it mean when a child has "paradoxical breathing" during sleep? how is it treated?

Chest IN & tummy OUT: In normal young children, both the chest and tummy expand when breathing in. With paradoxical breathing, the tummy expands when breathing in, but the chest gets sucked inward (downward). Paradoxical breathing can be normal in babies & toddlers because their chest cages are still "soft". After age 2-3 years, normal toddlers (without airway restriction) usually don't have paradoxical breathing.

Abnormal breathing: Paradoxical breathing is a condition where the person contracts the chest when inhaling, and expanding the chest when exhaling. This is usually a serious medical condition in children, involving an physical abnormality of the lungs, chest wall, or the innervation to one or both of them. This should be evaluated by your pediatrician, who will refer to a pulmonologist, who will need to do testing