Alzheimer’s disease is a progressive form of dementia that affects memory, thinking, and behavior. Learn about the causes, symptoms, treatments, and more. Alzheimer’s disease is a brain disorder that slowly impacts a person’s ability to think and remember. It worsens over time until it severely affects how those with the disease function and interact with the world. Alzheimer’s is rare before age 65, but past this age, the risk doubles about every five years. 1 However, many people live into their 90s and beyond without developing Alzheimer’s. Alzheimer disease, degenerative brain disorder that develops in mid-to-late adulthood. Alzheimer disease is characterized by a progressive and irreversible decline in memory and deterioration of other cognitive abilities. Learn more about the symptoms, causes, and treatment of Alzheimer disease. Alzheimer's disease (AD) is the most common cause of dementia, and involves a progressive degeneration of the cerebral cortex.
