Definition

The share of children under age 18 affected by asthma during the past year.

Children affected by asthma are defined as those who have ever been diagnosed by a doctor or health professional as having asthma and who still have asthma, and who experience one or more of the following: used medication for asthma in the past year, had moderate or severe difficulties due to asthma, had an asthma attack in the past year, and/or had been hospitalized for asthma in the past year.

Data Source

Child Trends analysis of data from the U.S. Department of Health and Human Services, Health Resources and Services Administration, Maternal and Child Health Bureau, National Survey of Children’s Health.

The state-level data used here come from the National Survey of Children’s Health (NSCH). The NSCH includes information on approximately 50,000 children under age 18, with representative samples for each state. For more information on the NSCH, see http://childhealthdata.org/learn/NSCH

Notes

S - Estimates suppressed when the 95% confidence interval is greater than 20 percentage points or 1.2 times the estimate.

N.A. – Data not available.

Percentages exclude missing data. Weighted percentages were applied to the estimates of those missing to derive overall estimates for the number of children.

Last Updated

2025-04