Allergic asthma develops at an early age, and patients often have atopic constitution that is allergic to certain substances, such as inhaling cold air, pollen, dust mites, etc.; eating fish, shrimp, milk, etc.; or coming into contact with certain medicines, such as penicillin. When these allergens enter the patient’s body, through a series of reactions, mast cells or basophils release sensitizing active substances, which act on the bronchial tubes, causing extensive small airway narrowing and wheezing symptoms. Most of the methods for detecting allergens are in vitro tests, including skin tests, puncture, blood tests and other methods, which do bring some help to the treatment, but there are certain limitations, the examination process is complicated, long time and limited scope, generally only 10 or so substances can be examined, and not all allergic substances can be extensively examined, that is to say, there will be missed, so that the prevention and treatment are not thorough enough. Cardiogenic asthma is a wheezing symptom in acute left heart insufficiency, easily confused with bronchial asthma, and the main points of differentiation between the two can be summarized as follows: 1, history: bronchial asthma has a history of asthma attacks, personal or family history of allergies; cardiogenic asthma has a history of hypertensive heart disease, coronary artery disease, rheumatic heart disease, or syphilitic cardiology history. 2, the age of onset: bronchial asthma is more common in adolescents; cardiogenic asthma is more common in middle-aged and old people. Season of onset: bronchial asthma occurs in spring and fall; cardiogenic asthma is not obvious. Lung signs: bronchial asthma is characterized by prolonged expiratory time, widespread rales, and white foamy sputum if sputum is present; cardiogenic asthma is characterized by more dry rales in both lungs and a large amount of pink foamy sputum. 5, cardiac signs: bronchial asthma without cardiac basis is normal; cardiogenic asthma can be seen in the left heart enlargement, gallop rhythm and pathological murmur. 6, chest X-ray: bronchial asthma lung field clear or translucency increased; cardiogenic asthma can be seen in pulmonary bruising and left heart enlargement. 7.Effective therapeutic drugs: β2 agonists and aminophylline for bronchial asthma; digitalis, morphine, diuretics and aminophylline for cardiogenic asthma.