Cough can easily appear in the late stage of the flu due to a combination of diseases such as increased airway sensitivity, which is caused by excessive air entering the airways, which is particularly sensitive, and the mucous membrane being occupied by too much air. Anti-infective drugs are very effective in these patients, and drugs that reduce the sensitivity of the airways can also be given, such as compound methocarbamol, which is a very good treatment for cough. It may also be due to bacterial and viral invasion after a cold, resulting in inflammation and some degree of edema around the mucous membranes. So when the cold is late, as the body gradually recovers and the mucous membrane of the respiratory tract is repaired, it stimulates the respiratory tract and causes a cough reflex as it discharges inflammatory substances and other secretions. Most patients with this condition can heal on their own and do not need special treatment for the time being. In addition, if the cold is not treated in time, it may cause infection of the lower respiratory tract and bronchitis, pneumonia, lung abscess and other diseases. Patients may have symptoms such as fever, coughing and breathlessness, etc. It is necessary to choose antibiotics with high sensitivity for treatment according to the examination results, and at the same time, give antipyretics, cough and phlegm medicines, etc. according to the patient’s condition.