This document provides information on dementia and various types of dementia such as Alzheimer's disease and vascular dementia. It discusses symptoms, brain changes, risk factors and diagnostic approaches for different dementias. Alzheimer's disease is the most common type of dementia, accounting for 60-80% of cases. Vascular dementia is the second most common, making up 20% of cases. Symptoms of Alzheimer's include memory loss and impaired judgment, while vascular dementia symptoms include impaired planning and reasoning abilities. Brain imaging can detect abnormalities associated with different dementias. A thorough diagnostic evaluation includes history, physical exam, neuropsychological testing, lab tests and brain imaging.