Cough is a symptom that helps to clear secretions or foreign bodies from the airways and is not necessarily related to the development of pneumonia. The main causes of cough include physical, inflammatory and psychogenic. Physical stimuli such as smoke inhalation, new organisms in the airway, and tracheal compression; inflammatory stimuli including airway inflammation, lung infection, and pulmonary exudation, often accompanied by coughing; and psychogenic stimuli such as stress and cold. The development of pneumonia depends on the pathogen and the host. Pneumonia can occur if the pathogen is abundant and virulent and/or if the host’s local and systemic immune defenses of the respiratory tract are compromised. Therefore, pneumonia does not necessarily occur with a severe cough. When the cough is severe, it is important to go to the hospital in a timely manner to clarify the cause of the disease and to treat it under the guidance of the doctor.