Coughing for how long does not form asthma, because cough and asthma, belong to different concepts. Cough is a defensive reflex and a symptom and response to disease, and many diseases can cause cough symptoms, especially respiratory diseases, such as the common cold, pharyngolaryngitis, tonsillitis, bronchitis, pneumonia, tuberculosis, bronchodilatation, and lung abscess. Asthma is a disease, a chronic inflammatory disease of the airways, involving a variety of cells and cellular components, the presence of airway hyperresponsiveness, and its clinical symptoms are mainly recurrent chest tightness, wheezing, dyspnea, or cough. Therefore, asthma can cause cough symptoms, but cough does not cause and form asthma, and its causal relationship cannot be reversed. If the cough is caused by pneumonia, tuberculosis and other diseases, no matter how long the cough will not form asthma, the symptoms and diseases should not be confused with each other.