For the study, researchers screened more than 800 children and teens with severe and persistent wheezing -- a whistling or rattling sound that occurs while breathing.

Wheezing is a sound arising from the airways due to an obstruction or narrowing, which prevents the free flow of air.

When your baby is wheezing, they might take tiny breaths accompanied by a whistling sound. Because of a baby’s small airways, many things can cause them to make a wheezing sound when they ...