To assess the prevalence of bullying behaviors and morbidities, including overweight/obesity and frequent physical and emotional symptoms, and the associations between such morbidities and frequent involvement in bullying behaviors among US adolescents in grades 6 through 10. Design, Setting, and Participants'. This study was based on an analysis of US data from the 1998 World Health Organization Health Behavior in School-aged Children survey. The survey provides nationally representative, cross-sectional survey information on 15,686 US students in grades 6 through 10. Outcome Measures: Involvement in bullying as a victim and/or as a bully; body mass index; and self-reported headaches, stomachaches, backaches, dizziness, irritability, "feeling low", "feeling nervous", and sleeping difficulties. Results: Fifteen per cent of the students were involved in bullying others and/or were victims of bullies at least once a week. The bullying activities took place both at school and elsewhere. Students who suffered from at least one or more frequent physical or emotional symtom, occuring several times a week, were at 2.4 to 3.5 times more likely to be involved in frequent bullying incidents, as compared to students, who did not experience frequent symptoms. Conclusions: The present study confirmed that frequent participation in bullying behaviors, as a bully, a victim, or both, was associated with poor health status. The existence of a morbidity spectrum associated with participation in bullying behaviors is important information for pediatric practice and merits further investigation.the victims of such behaviors, or who may be both bully and victim (2-16). These reports demonstrate that both victims and perpetrators of bullying are significantly more likely than their peers, who are not involved in bullying, to suffer from one or more physical and/or emotional symptoms. This range of morbidity includes headache, Brought to you by | University of Arizona Authenticated Download Date | 5/30/15 12:24 PM