The National Center for Health Statistics (NCHS) of the Centers for Disease Control (CDC) provides a large amount of information from its data systems by way of the NCHS Series Reports. Two reports recently provided a comprehensive description of the prevalence of asthma in the United States as revealed in NCHS data. The NCHS data describes also the utilization of health care by asthmatic subjects, morbidity and mortality in the United States due to asthma, populations at risk, factors that may have contributed to trends of increasing rates, and problems with national asthma surveillance. The recent increase in illness and deaths from asthma as described by the NCHS data systems suggests important changes that need further study. The role of subpopulations in this decade of increasing morbidity and mortality needs to be considered. These recent changes in asthma may be driven by single or multiple causes, including increasingly frequent, increasingly severe, or new environmental exposures; changes in medical care, such as pharmacotherapy; or inadequate access to high quality health care.