Coughing three or four days after a cold may be one of the clinical symptoms of the disease, or it may be caused by the development of tracheo-bronchitis, bronchopneumonia and other complications. Colds are generally viral infectious diseases of the upper respiratory tract, mainly caused by viral invasion of the mucous membrane of the nasopharynx triggered by the local inflammatory reaction, which can be manifested as nasal congestion, runny nose and other symptoms, most of which will start with a cough. If the cough occurs three or four days after the cold, the cough symptoms are mild, slightly cough sputum, generally belong to the common process of cold course changes. If a person with a cold develops a cough three or four days after catching a cold and the cough worsens progressively, accompanied by wheezing, chest pain and other discomforts, then it is considered that there may be complications such as acute trachea-bronchitis or bronchitis-pneumonia, etc., and it is necessary to go to the hospital, complete the relevant examinations, and follow the doctor’s instructions for treatment after the condition has been clarified. Cough can be caused by a variety of diseases, if the symptoms are not relieved or aggravated, it is recommended to consult a doctor in a timely manner to clarify the cause of the disease, and use medication under the guidance of the doctor, so as to avoid delays in the condition.