Paradoxical breathing is when your chest moves inward during inhalation instead of outward and outward during exhalation which is the opposite of normal breathing patterns.
Paradoxical breathing can be a sign of possible serious respiratory issues or even injures and often does require immediate medical attention.
During normal breathing unlike paradoxical breathing your chest expands outwards as you inhale, and allows air to enter your lungs and then as you exhale the chest should contract inwards and force air out.
When you're experiencing paradoxical breathing your chest instead moves in the opposite direction, with your chest sinking in during inhalation and then rises during exhalation.
A variety of things can cause paradoxical breathing which include fractured ribs or other chest injuries, damage to the nerves that control the diaphragm or other respiratory muscles which can disrupt normal breathing patterns.
Blockers in your upper airway like choking or swelling can also cause paradoxical breathing.
Weak respiratory muscles which support breathing can lead to abnormal breathing patterns and paradoxical breathing.
Paradoxical breathing in infants and children can be normal during REM sleep as a result of a soft ribcage they have.
Other symptoms can also accompany paradoxical breathing and can be a sign of respiratory distress such as, difficulty breathing or rapid breathing, grunting or wheezing, blue skin color, and retractions meaning that the skin sinks into the ribs during breathing.