Dementia is a loss of brain function that occurs with certain diseases. It affects memory, thinking, language, judgment, and behavior.
Most types of dementia are nonreversible (degenerative). Nonreversible means the changes in the brain that are causing the dementia cannot be stopped or turned back. Alzheimer's disease is the most common type of dementia.
Lewy body disease is a leading cause of dementia in elderly adults. People with this condition have abnormal protein structures in certain areas of the brain.
Dementia also can be due to many small strokes. This is called vascular dementia.
The following medical conditions also can lead to dementia:
Dementia usually occurs in older age. It is rare in people under age 60. The risk for dementia increases as a person gets older.
Dementia symptoms include difficulty with many areas of mental function, including :
Dementia usually first appears as forgetfulness.
The early symptoms of dementia can include: