Smoking & Phlegm

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Smoking has a number of well-known health effects. The Centers for Disease Control and Prevention warns that it causes lung cancer and increases stroke and heart disease risk. It restricts circulation and contributes to conditions like abdominal aortic aneurysm and peripheral vascular disease. Some effects are more subtle. For example, the University of Pittsburgh Medical Center, or UPMC, reports that cigarettes affect phlegm production.


Mucus is a body secretion that helps protect the lungs by trapping foreign bodies that get in the nose while a person is breathing, according to Word IQ. Certain actions and illnesses cause increased mucus production. A large amount of thick mucus is known as phlegm. It can result from colds and respiratory infections, and the UPMC states that smoking can cause it.


The UPMC explains that smoking leads to phlegm because of the way it affects the lungs. Smokers develop more mucus-producing cells in their lungs and airway. They have a greater mucus volume, which becomes thick phlegm. The lungs are normally cleaned by hairs called cilia, but their movement slows while a person is smoking and remains impaired for several hours afterward. Cilia cannot clean out the phlegm effectively, so it remains in the lungs and airway.

Short-Term Effects

Phlegm that stays in the lungs and airway clogs them and leads to chronic coughing. It can also cause respiratory infections, the UPMC warns. The problem often gets worse because cigarette use reduces the number of cilia and inflames and narrows the lungs and airway. Air flow is eventually reduced. Smoking Cessation, a stop-smoking website, states that smokers tend to cough in the morning because their cilia are very active in the morning. Their efforts to clear out accumulated phlegm causes coughing. Non-smokers who are regularly exposed to secondhand smoke suffer from these same effects, according to the UPMC.

Long-Term Effects

Smokers have a higher risk of developing certain respiratory diseases like emphysema and chronic bronchitis over time. Phlegm complicates these problems, according to the UPMC. Both diseases cause breathing problems, and the increased production of thick mucus further restricts airflow. Smoking Cessation explains that smoking eventually thickens lung membranes. This change is linked to an increased throat cancer risk.


People who stop smoking realize many benefits, including reduced phlegm. The UPMC explains that those who stop smoking can breathe more easily within three cigarette-free days. Phlegm is noticeably reduced within one month, and cilia regrow within one to nine months. Cilia regain the ability to handle mucus and clean the lungs efficiently, and coughing and infection risk drops.