The common reasons for coughing when the air conditioner is on are as follows: 1. First of all, you need to go to the hospital to check the blood count and observe whether there is an elevation of eosinophils, if there is an elevation of eosinophils, it is likely that the cough is caused by allergies, because the microbial, bacterial or viral content in the air conditioner is relatively high, because the air conditioner cleaning is not very timely, it is easy to cause the microbial host This can cause allergies to occur. If the cough is caused by allergies, it should be treated with anti-allergy medication, such as Desloratadine.2. Coughs caused by cough variant asthma cannot be ruled out, as the bronchodilator test or bronchial excitation test should be checked for cough variant asthma. The coughing symptoms will be triggered by cold air irritation or microorganisms in the air conditioner, and will require nebulized inhalation of bronchodilators and glucocorticoids for treatment.