Dementia isn't a specific disease. Instead, it describes a group of symptoms affecting intellectual and social abilities severely enough to interfere with daily functioning. It's caused by conditions or changes in the brain. Different types of dementia exist, depending on the cause. Alzheimer's disease is the most common type.
Memory loss generally occurs in dementia, but memory loss alone doesn't mean you have dementia. Dementia indicates problems with at least two brain functions, such as memory loss along with impaired judgment or language. Dementia can make you confused and unable to remember people and names. You may also experience changes in personality and social behavior. However, some causes of dementia are treatable and even reversible.