What is the cause of coughing when cold air is encountered

It is considered that when the throat or bronchus of the patient encounters cold stimulation, it will cause spasm of bronchial smooth muscle, which will cause the patient to cough as soon as it encounters cold air. However, it is not excluded that the patient has developed cough variant asthma and other diseases. It is recommended that the patient go to the hospital for examination to clarify the cause.