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Medical Author:

Michael C. Fishbein, MD

Michael C. Fishbein, MD

Dr. Fishbein received his undergraduate and medical degrees from the University of Illinois. He completed a residency in anatomic and clinical pathology at Harbor General Hospital/UCLA Medical Center. He is board certified in anatomic and clinical pathology.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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In this Article

• Smoker's lung introduction
• What is the structure of the normal lung?
• What processes determine normal function of the lung?
• What are the abnormalities (diseases) in smoker's lung?
• What happens to the lung in emphysema?
• How does emphysema come about?
• Why does smoker's lung look black?
• What happens to the airways in chronic bronchitis?
• Are smokers with COPD predisposed to developing pneumonia?
• What about lung cancer in smokers?
• Are any of the pulmonary consequences of smoking reversible?
• From what do smokers die?
• Patient Comments: Smokers' Lung - COPD
• Smoker's Lung: Pathology Photo Essay Index

In chronic bronchitis, smoke damages the cells that line the airway (epithelial cells). Nicotine is one of the many components of cigarette smoke that is directly toxic to the lining cells of the airway. (Of course, the nicotine is also addictive.) The tissue damage attracts inflammatory cells. These cells then release enzymes that further damage the lining cells of the airway and stimulate goblet cells to increase in number and to increase mucus production. Figure 6 is a microscopic section of a bronchial wall in a smoker with chronic bronchitis.

Figure 6: BRONCHIAL WALL IN CHRONIC BRONCHITIS

The major consequence of chronic bronchitis is airway obstruction. In fact, this figure demonstrates mucus and debris blocking the bronchial airway. Indeed, the most important cause of airway obstruction in chronic bronchitis is blockage by mucus, inflammation, progressive scarring (fibrosis), and/or narrowing (constriction) of the airways. As a result of the bronchial blockage, gases cannot get to and from the alveoli. In other words, chronic bronchitis interferes with ventilation.

It is important to know that people with asthma likewise have chronic bronchitis with airway obstruction. In asthma, however, the cause of obstruction is somewhat different and the obstruction usually occurs in attacks that are reversible. In any case, both smokers and asthmatics with bronchitis may cough, wheeze, and spit up thick mucus (sputum) from the lung.