Starting to cough after a cold has healed may be due to airway hyperreactivity, or it may be due to bacterial, viral, mycoplasma, and other infections leading to bronchitis, pneumonia, or allergic cough, postnasal drip, and other causes. 1. Airway hyperreactivity can occur after a cold and is related to the fact that the airway mucosal damage has not yet recovered, and the patient may show signs such as coughing when stimulated by irritating gases. 2. Bronchitis, pneumonia: after a cold is cured, the body’s immunity is still poor, bacteria, viruses, mycoplasma and other pathogens are prone to invade the organism, resulting in bronchitis or pneumonia and other diseases, coughing and coughing up sputum and other symptoms may occur. 3. Allergic cough: after the cold is cured, if the body resistance is relatively poor, contact with allergens leading to allergic cough, there may be paroxysms of irritating dry cough symptoms. 4. Postnasal drip: chronic rhinitis patients, after a cold is completely cured, bacterial, viral infections or allergies and other causes of rhinitis recurrence, frequent sneezing, runny nose and other symptoms, nasal discharge backflow stimulation to the throat may cough. After the cold is cured and cough symptoms begin to appear, you should go to the hospital for examination to determine the cause of the disease and timely treatment.