Narrowing of the larynx leads to stridor, increased respiratory rate, respiratory retractions, and a barking cough. Symptoms worsen at night and peak between 24 and 48 h. In most cases it improves ...

A narrowing of the smallest airways in the lung (bronchioles) causes wheezing. This narrowing results from swelling caused by a virus. The respiratory syncytial virus (RSV) causes most bronchiolitis.