—An attack consists of the narrowing of the bronchioles, which is caused by a muscle spasm, an enlargement of the mucous membrane and by abundant mucous secretions. Asthma can be caused by allergins of natural origin such as pollen as well as manmade pollutants.
—These two diseases are discussed together because they either occur simultaneously
emphysema may be the follow-up to bronchitis. In emphysema, the victim’s air sacs or alveoli become enlarged and eventually break down or burst. Both bronchitis and emphysema induce shortness of breath in victims. In advanced cases victims are unable to blow out a lighted match only a few inches away from their mouths.
—Cancer is produced by uncontrolled cell growth. Lung cancer is the abnormal and uncontrolled growth of cells which usually originates in the bronchial mucous membranes. A multitude of carcinogenic substances are known . The best known are the hydrocarbons which are present in the air in cities and industrial areas.