When the acute phase of respiratory infection symptoms disappear, the cough is still prolonged, mostly manifested as irritating dry cough or cough a small amount of white mucus sputum, usually lasts for 3 to 8 weeks, X-ray chest X-ray examination is not abnormal, known as post-infectious cough. Among them, the cough caused by viral colds is the most common, also known as “post-cold cough”. Because of the high reactivity of the airway caused by colds, coughing can be caused by external stimuli or cold air. It is advisable to wear a mask when going out and to pay attention to the cleanliness of the indoor environment, avoiding exogenous stimuli such as pollen, animal fur and oil smoke. Coughing after a cold is a self-limiting illness that usually resolves gradually over time. There is no specific treatment available. For some patients with obvious cough symptoms, short-term application of cough suppressants, antihistamines plus decongestants is recommended.