A cough that has been bad for three months is likely to be chronic bronchitis or bronchiectasis, both of which can be diagnosed with a chest CT. In the acute stage of chronic bronchitis, the treatment is often cough suppressant and anti-infective, which can be done with cephalosporin antibiotics and amiloride oral solution to reduce phlegm. If the cough is prolonged due to bronchiectasis, it is often necessary to treat the cough with sputum removal in the morning. Patients can adopt a froggy position to facilitate the expulsion of sputum and reduce the incidence of infection. In addition, the cause of coughing for three months may be cough variant asthma, and the patient should be taken for a bronchodilator test or bronchial excitation test. Inhalation of Symbicort to relieve cough symptoms.