Cough more than a year bad may be lung disease, chronic bronchitis, cough variant asthma caused. 1. Lung diseases: tuberculosis, lung tumors and other diseases, the lungs will be stimulated by inflammation of organic lesions, may appear cough for more than a year is not good. 2. Chronic bronchitis: chronic bronchitis is a chronic disease, the onset of relatively slow, inflammation stimulation to the bronchial area will cause reflex cough, thus coughing for more than a year is not good. 3. Cough variant asthma: when respiratory tract infections or other stimuli, such as hair, pollen, etc., leading to bronchial asthma, will lead to high airway reactivity, resulting in coughing, and variant asthma will be recurrent, coughing time delay. Cough for more than a year is not good may also be due to other diseases, it is recommended to go to the hospital as soon as possible, follow the doctor’s advice and active treatment.