Cough with phlegm for a long time is not good may be related to bronchiectasis, malignant tumors, cough variant asthma and other reasons. 1. Bronchiectasis: Bronchiectasis is a general term for a heterogeneous group of diseases in which the bronchi are abnormally and persistently dilated, which is mainly characterized by persistent or recurrent coughing, coughing up sputum or coughing up purulent sputum. The sputum is mucoid, mucopurulent or purulent and may be yellowish-green in color. Therefore, patients with bronchiectasis may have long-term cough and sputum symptoms. 2. Malignant tumors: such as lung cancer, which is a malignant tumor originated from the bronchial mucosa or glands in the lungs, patients may have long-term coughing and sputum coughing phenomenon, and need to undergo the relevant examination to make a clear diagnosis. 3. Cough variant asthma: it is a special type of asthma, which can be triggered by emotional excitement, strenuous exercise, contact with allergic substances, etc. Cough is the only or the main clinical manifestation without obvious symptoms such as wheezing and shortness of breath, etc. Coughing can be accompanied by an increase in secretion and the formation of sputum, which leads to long-term coughing and phlegm. Cough and phlegm can also be seen in other diseases such as chronic obstructive pulmonary disease, if the symptoms do not improve, it is recommended to go to the hospital for relevant examinations to determine the specific cause of the cause of treatment.