Dementia describes the state of a person’s mental function. It’s not a specific disease. It’s a decline in mental function from a previously higher level that’s severe enough to interfere with daily living.
A person with dementia has two or more of these specific difficulties, including a change or decline in:
Memory.
Reasoning and handling of complex tasks.
Language.
Understanding visual form and space relationship.
Behavior and personality.
Dementia ranges in severity. In the mildest stage, you may notice a slight decline in your mental functioning and require some assistance on daily tasks. At the most severe stage, a person depends completely on others for help with simple daily tasks.
Dementia develops when infections or diseases impact the parts of your brain involved with learning, memory, decision-making or language. Alzheimer’s disease is the most common cause of dementia, accounting for at least two-thirds of dementia cases in people 65 and older.
Other common causes of dementia include:
Vascular dementia.
Dementia with Lewy bodies.
Frontotemporal dementia.
Dementia due to Parkinson’s disease.
