The bronchial tubes become swollen and inflamed, and their diameter may decrease markedly. Excessive amounts of sputum are characteristic of bronchitis, and this may further impair air movement. Finally, the lungs become like large floppy balloons, with a major effort necessary to squeeze out each breath. In some cases, eventhat air that is breathed in and out fails to transmit its life giving oxygen normally, since it comes into contact with scar tissue or sputum instead of healthy lung tissue. An additional result in severe cases is that the carbon dioxide produced in the body by everyday metabolism can no longer be exhaled adequately, and accumulates in the blood.
Some individuals are more sensitive to nicotine and to cigarette smoke than are others.
In addition, an occasional nonsmoker may develop the syndrome, either through congenital chemical imbalances, occupational exposures, or unknown factors. The first symptom of emphysema is usually shortness of breath on exertion. Chronic bronchitis usually has a longstanding cough as its first warning. Most patients have a mixture of the two. As the disease progresses, shortness of breath increases such that in the end, even speaking more than a few words at a time is too much.