The prevalence of pediatric health conditions is increasing. This upsurge is due, in part, to advances in medical treatments that have improved outcomes for youth with some of these illnesses (e.g., cystic fibrosis, sickle cell disease) and, in part, to environmental changes that have raised the risk for pediatric conditions (e.g., obesogenic environments that lead to greater risk of obesity and various medical comorbidities). Between 10 and 20 percent of youth have a chronic illness such as asthma, cancer, or diabetes, and approximately a third of youth are overweight or obese ( Van Cleave, Gortmaker, and Perrin 2010 ). In addition to rising numbers of youth with chronic illness, evidence suggests that the burden of these illnesses on families and communities is on the rise. For example, youth are experiencing health complications associated with disease at younger ages and requiring hospital interventions more often. Family functioning is frequently affected by a child's experience of a pediatric condition and its consequences. Similarly, families have an important impact on the child's condition, both how it is experienced and the likely health outcomes associated with the condition.