Dementia is an umbrella term used to indicate various symptoms that can affect the functioning of normal life by disrupting normal and intellectual thinking and functioning. According to the Diagnostic & Statistical Manual of mental disorders (DSM), dementia is diagnosed when at least two or more functions of the intellectual functioning are impaired or affected. These could include normal perception, memory, judgment or language.

Some people may even experience problems with reasoning and behavioral control. Based on the symptoms that the person shows, there are a lot of different classifications for dementia. Some of the most common classifications include the cortical, subcortical, progressive, primary and secondary classes.