A few months baby cough for several months are not good may be related to pneumonia, variant asthma, chronic bronchitis and so on. 1. Pneumonia: bacteria or viruses cause pediatric pneumonia, if not controlled in time, may turn into chronic pneumonia, its cough cycle is relatively long, generally more than three months of pneumonia become chronic pneumonia. 2. Variant asthma: airway hyperresponsiveness caused by allergy, heredity and other factors, most of the patients are due to persistent coughing or recurrent episodes, resulting in prolonged coughing, causing this disease. 3. Chronic bronchitis: there may be mycoplasma infections and other factors, resulting in damage and chronic inflammation of the trachea and bronchial mucosa, resulting in long-term cough. A few months baby cough for several months are not good, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.