The main reasons for coughing in the cold are normal physiological phenomena, upper respiratory tract infections, bronchial asthma and so on. 1. Normal physiological phenomenon: normal human respiratory tract in the inhalation of cold air will protect the cough, so as not to inhale more cold air caused by discomfort, generally into the warm environment can be relieved on their own. 2. Upper respiratory tract infections: such as acute bronchitis, bronchitis, pharyngitis, rhinitis, common cold, etc., cold air can induce cough aggravation, accompanied by coughing up sputum, sore throat, fever, runny nose and other symptoms. 3. Bronchial asthma: bronchial asthma patients often irritating dry cough, no sputum, at the same time the lungs can hear rales, often induced by cold air, dust mites, pollen. Cold on the cough causes more, the patient should be to the regular hospital, clear cause, early treatment, so as not to delay the condition.