Croup isn’t one disease — it’s a symptom caused by common viruses like parainfluenza, flu, or RSV. One simple treatment — a single dose of steroids from your pediatrician — can calm the swelling in the airway and prevent that scary ER visit. But if your child is struggling to breathe, making a high-pitched sound that doesn’t ease after a few minutes, that’s an emergency. Get help right away. So remember: know what it is, know when it’s urgent, and know the treatment that can protect your child.