Delirium is one of the most important syndromes in geriatric medicine, with its potentially unfavorable prognosis increasingly recognized. At least 10-20% of older adults treated in hospitals are affected, but delirium is also common in nursing homes and among individuals with dementia. This book addresses delirium in terms of symptom spectrum, classification, etiology, and pathogenesis. Diagnostic and therapeutic approaches are discussed based on current evidence-based knowledge. Specific chapters focus on delirium in substance use disorders and the current state of knowledge regarding delirium prevention. Numerous case descriptions, tables, and illustrations, along with the discussion of current healthcare policy issues relevant to geriatric medicine beyond delirium, provide a close practical connection for all professionals in geriatrics and gerontology.