The presence of croup when a child breathes is primarily a sign of airway spasm. The common causes of airway spasm are infection, airway allergy, and foreign body obstruction. In case of airway spasm, the symptoms can be relieved by nebulized inhalation of Bolicam and Pramipexole, but it is more important to remove the cause. Blood tests, chest X-ray and nitric oxide breath test should be completed to clarify the etiology. Infection caused by infection is mainly treated with anti-infection and sputumification. Airway allergy requires the use of hormonal anti-inflammatory, including intravenous and nebulized inhaled hormones, and anti-allergy drugs. Airway foreign bodies are usually sputum boluses, peanuts, bones and other choking exogenous foreign bodies, when relief and treatment must be achieved by bronchoscopy and removal of foreign bodies.