CLRD actually comprises three major diseases, i.e., chronic bronchitis, emphysema, and asthma, that are all characterized by shortness of breath caused by airway obstruction. The obstruction is irreversible in chronic bronchitis and emphysema, reversible in asthma. Before 1999, CLRD was called Chronic Obstructive Pulmonary Disease (COPD). Just as cigarette smoking has increased among women, it has also increased among minority populations. While in 1998 COPD ranked ninth as a cause of death among Hispanics and eighth among African-Americans, compared to fourth among whites, this is expected to change as the rates of smoking in these groups increase, according to CDC statistics.