Two-year-old baby airway hyperreactivity consider the possibility of bronchial asthma, belongs to a kind of disease. Bronchial asthma is referred to as asthma, chronic airway inflammation, airway hyperreactivity is the basic feature of asthma, the latter refers to the airway to a variety of stimuli such as allergens, physical and chemical factors, exercise and drugs, etc. present a highly sensitive state, to a certain extent, reflecting the severity of the inflammation of the airway. Asthma is a common chronic respiratory disease in childhood, often characterized by recurrent episodes of wheezing, chest tightness, shortness of breath, or coughing, often at night, early in the morning or exacerbated, and in most children relieved on their own or with treatment. Asthma can occur at any age, 30% of children have symptoms at the age of 1 year, 80% to 90% of children with asthma first symptoms before the age of 4 to 5 years, some children have a family history of the onset of atopic or allergy-related, most of the children with infantile eczema, allergic rhinitis, food (drug) allergy history. If asthma in children is not diagnosed and treated in a timely manner, irreversible changes in the airways can occur with the development of the disease. Therefore, two-year-old babies with symptoms of airway hyperresponsiveness need to consult a doctor in a timely manner, after a clear diagnosis, timely targeted treatment, so as not to miss the opportunity for treatment.