People with severe disabilities have a higher prevalence of many health conditions when compared with the general population. Examples include gastrointestinal conditions, chronic allergies, epilepsy, and sleep dysregulation, among many other health concerns. Of particular interest in the treatment of challenging behavior is the comorbidity of health conditions and behavioral challenges. Evidence suggests that not only do people with severe disabilities have higher rates of health conditions, but people with severe disabilities and challenging behavior have even higher rates of health concerns. This article reviews the existing evidence linking health conditions and challenging behavior, discusses health disparities in diagnosis and treatment of these comorbidities, and suggests future avenues for discovery and intervention.