Key Findings: Overall, more than one in five middle school students report having a disability or chronic illness diagnosed by a doctor, and for nearly 4% of middle school students, this condition limits their participation in school; asthma and allergies are by far the most commonly reported conditions among students; students who report having a disability or chronic illness experience difficulties with certain daily tasks more frequently than their peers, especially if their condition limits their participation in school; the proportion of students reporting a chronic illness or disability increased slightly between 2010 and 2014.