Unhealthy dietary behaviors, physical inactivity, and tobacco use contribute to chronic disease and other health conditions, including obesity, diabetes, and asthma. These behaviors often are established during childhood and adolescence, extend into adulthood, are interrelated, and are preventable. The Youth Risk Behavior Surveillance System (YRBSS) monitors priority health-risk behaviors, general health status, and the prevalence of overweight and asthma among youth and young adults. YRBSS includes a national school-based survey conducted by CDC and state and local school-based surveys conducted by state and local education and health agencies.