Cough triggered by exposure to cold air may be related to cough variant asthma, pharyngitis, allergies and other causes. 1. Cough variant asthma is the more common cause. Such patients due to the existence of airway hyperresponsiveness, so once exposed to cold air can be triggered, resulting in a cough performance, and the degree of coughing is generally more intense. 2. pharyngitis, whether acute pharyngitis or chronic pharyngitis, can make the pharyngeal part of the inflammatory reaction, and thus more sensitive to cold air. Once the stimulus is received, it can induce coughing. 3. Allergy, including allergic cough, can be induced under the stimulation of cold air cough, need to improve the allergen examination and other timely treatment.