Symptoms and Signs of Croup

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 3/11/2019

Doctor's Notes on Croup

Croup is a type of viral infection of the upper respiratory tract that results in inflammation, increased mucus production, and swelling of the upper airways. It is one of the most common causes of respiratory distress in young children, particularly children aged 6 month to 3 years. The illness is rarely seen in adults because their breathing passages are larger and can accommodate the inflammation without accompanying symptoms. Common viral causes of croup include parainfluenza (most common cause), influenza, adenovirus, respiratory syncytial virus (RSV), and rhinovirus.

Symptoms of croup include a cold, cough, and low-grade temperature lasting two to three days. By day three, a barking cough (sounds like a seal) that worsens at night is usually present. Other symptoms of croup include stridor (wheezing on inhalation), hoarseness, difficulty swallowing, and respiratory distress.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.