Cough variant asthma is a common clinical type of bronchial asthma and is clinically very common in patients with chronic cough, but there is a problem of under- and over-diagnosis. Physicians with insufficient knowledge of this disease are prone to underdiagnosis and often treat it as a cold or acute bronchitis, applying antibiotics and other treatments with poor clinical outcomes. There are important differences between cough variant asthma and cough after common cold or cough caused by acute bronchitis, as the cough of cough variant asthma patients is often seasonal, tends to occur during the seasonal change or pollen season, cough is more severe at night or in the early morning, often combined or with previous allergic rhinitis, and patients often have certain family history. Diagnosis: Pulmonary function airway excitation tests and nitric oxide in the breath can aid in the diagnosis. A positive excitation test is the golden indicator for the diagnosis of the disease. Recognizing the characteristics of this disease allows to distinguish it from cough caused by common cold or acute bronchitis. However, parallel to the underdiagnosis there is the problem of overdiagnosis. Some doctors, recognizing the common line of this disease, are unable to perform an excitation test due to conditions and other reasons, and diagnose cough variant asthma based on symptoms and high nitric oxide in the whistle, ignoring the diagnosis of eosinophilic cough, which is basically similar in treatment, but eosinophilic cough, for which the excitation test is negative, has recurrent Although the treatment is basically similar, eosinophilic cough, with negative provocation tests, rarely develops into typical bronchial asthma, which is distinctly different from cough variant asthma, which is easily transformed into typical bronchial asthma, and also distinctly different from the level of inflammatory cell invasion.