Dementia is a general term for a decline in cognitive function severe enough to interfere with daily life, affecting memory, reasoning, language, judgment, and behavior. It is not a single disease but a syndrome caused by various underlying conditions, most commonly Alzheimer’s disease, as well as vascular dementia, Lewy body dementia, and other neurodegenerative disorders. Symptoms typically develop gradually and may include memory loss, confusion, difficulty with communication, personality changes, and impaired ability to perform familiar tasks. Risk increases with age, though dementia is not a normal part of aging. While there is currently no cure for most forms of dementia, early diagnosis, medication, supportive therapies, and structured care can help manage symptoms and improve quality of life.