Chest X-ray cannot show asthma, although bronchial asthma is a chronic inflammation of the airways, but if the bronchial asthma is not co-infected, chest X-ray and lung CT have no abnormalities. The diagnosis of bronchial asthma is mainly based on the patient’s symptoms, signs and auxiliary examination to confirm the diagnosis. Symptoms of bronchial asthma are typically episodes of wheezing, shortness of breath, dyspnea, cough, chest tightness, etc. Physical examination reveals symmetry of the chest, and rales at the end of expiration can be detected in both lungs. Adjunctive examination is mainly to see the lung function, lung function bronchodilator test or bronchial excitation test is positive, blood routine shows high eosinophils, IgE may also be elevated, bronchial asthma may be related to allergies.