Among the common respiratory diseases in children, the prevalence of bronchial asthma is 10%, double the rate in adults and increasing in the last 5 years. Particularly in children under 2 years old, this rate is even higher.

Asthma is a chronic inflammatory disease of the airways, which is very sensitive to various irritants. If a child with asthma is exposed to irritants, the airways - mainly the bronchi - will swell, constrict, fill with mucus, so they will become blocked, causing the patient to have a cough, wheeze, and difficulty breathing.