Dementia, also known as
senility, is a broad category of
brain diseases that cause a long term and often gradual decrease in the ability to
think and remember that is great enough to affect a person's daily functioning. Other common symptoms include emotional problems, problems with
language, and a decrease in
motivation. A person's
consciousness is usually not affected. A dementia diagnosis requires a change from a person's usual mental functioning and a greater decline than one would expect due to aging. These diseases also have a significant effect on a person's caregivers.