Taken together, asthma and chronic obstructive pulmonary disease — which includes chronic bronchitis and emphysema — affect nearly 50 million Americans, or about 15% of the total U.S. population, according to statistics from such organizations as the Centers for Disease Control and Prevention. And combined, the two diseases cause more than 100,000 deaths per year. Fortunately, however, there is a wide range of treatments available for both, many of which work for both diseases.