Cigarette smoking can cause coughing, which can be phlegmless or with phlegm. 1. Cough without phlegm: mainly because tobacco smoke contains nicotine, carbon monoxide and other toxic and harmful substances, stimulate the throat caused by coughing symptoms, not accompanied by coughing phlegm. 2. Cough with sputum: mainly due to long-term smoking may lead to chronic pharyngitis, chronic bronchitis and chronic obstructive pulmonary disease, etc., when smoking smoke will induce inflammation of the pharynx and mucous membranes of the airway, resulting in increased secretion, and coughing and coughing symptoms. Whether or not a smoker coughs up phlegm varies from person to person, but in either case it is recommended to reduce or quit smoking, as the harmful substances contained in the smoke are not beneficial to your own health or the health of those around you.