Stridor is when your child breathes in, you hear a harsh, raspy sound. This happens with severe croup. Croup is a viral infection of the vocal cords.
Stridor occurs as the opening between the cords becomes more narrow.
First Aid for Attacks of Stridor With Croup Inhalation of warm mist. Warm, moist air seems to work best to relax the vocal cords and break the stridor. Take your child into a foggy bathroom. Have a warm shower running with the bathroom door closed. If your child continues to have stridor 20 minutes after mist treatment, call 911.