Allergic rhinitis and asthma often coexist. It has been reported that half of those who suffer from allergic rhinitis have asthma. An important cause of asthma is due to allergens. Patients with allergic rhinitis are particularly sensitive to certain allergens and cold air, such as pollen, dust, mites, mold spores and irritant gases, which can rapidly produce type I allergic reactions, resulting in nasal congestion, nasal and pharyngeal itching, sneezing, runny nose, coughing and other symptoms, followed by phytodystrophy, increased airway reactivity and bronchial smooth muscle contraction. The symptoms such as chest tightness, wheezing and expiratory dyspnea will appear soon. It can be seen that allergic rhinitis and asthma are two different diseases caused by one etiology. It can also be said that they are two different stages of a disease, i.e. allergic rhinitis is the precursor and asthma is the result. Both are type I allergic reactions, and the pathological basis is allergic inflammation with eosinophil infiltration and airway hyperreactivity. Most asthma can be significantly improved by standard treatment of allergic rhinitis; conversely, active prevention and treatment of allergic rhinitis can also reduce the occurrence of asthma, so the two are very closely related.