It is increasingly recognized that medical conditions can have a range of neurocognitive, psychosocial, and functional implications, even in the absence of obvious neurological involvement. Filling a gap in the literature, this comprehensive clinical reference reviews current research and provides clear guidelines for assessment and intervention. Chapters organized around major bodily systems—for example, cardiovascular, endocrine, immune/lymphatic—probe neurocognitive impairments associated with prevalent health conditions and their treatments, including coverage of COVID-19. State-of-the-science chapters on lifestyle behaviors and habits explore the neurocognitive impact of sleep and fatigue, nutrition and weight, acute and chronic pain (and the use of opioid analgesics), personality and temperament, and substance misuse.