Dementia is a descriptive term for a collection of symptoms that affect the brain. People with these symptoms may experience cognitive difficulties, personality changes, and behavioral problems. While these problems most often affect the elderly, they are not a normal part of aging. Alzheimer's disease is the most common cause, but many other conditions can cause these problems as well. In certain cases, drugs are available to improve symptoms and slow their progression, but these medications cannot provide a cure.
What Is Dementia?Dementia is not a specific disease. It is a descriptive term for a collection of symptoms (such as personality changes, behavioral problems, and memory problems) that can be caused by a number of conditions that affect the brain. All forms of dementia result from the death of nerve cells or the loss of communication among these cells.
Although Alzheimer's disease and certain other conditions are technically causes of dementia, they are also often referred to as types of dementia. Likewise, terms such as "vascular dementia" are often used to describe causes as well as types of dementia.
What Causes It?The human brain is very complex, and many factors can interfere with its functioning. Although scientists have uncovered many of these factors, they have not yet been able to fit these puzzle pieces together in order to form a complete picture of how dementias develop.
There are many possible causes of dementia. The most common cause is Alzheimer's disease. Over 50 percent of people diagnosed with dementia have Alzheimer's disease. Other causes can include:
- Multi-infarct dementia (a type of vascular dementia caused by a disruption of blood flow to the brain)
- Other types of vascular dementia (such as Binswanger's disease)
- Lewy body dementia
- Frontotemporal dementia
- Huntington's disease
- Creutzfeldt-Jakob disease.
Other conditions that can also cause dementia or dementia-like symptoms include:
- Reactions to medications
- Metabolic problems, such as hypothyroidism
- Nutritional deficiencies, such as vitamin B12 deficiency
- Infections, including HIV/AIDS
- Brain tumor or brain cancer
- Heart and lung problems
- Anoxia or hypoxia (conditions in which the brain's oxygen supply is either reduced or cut off entirely).
Although dementia is common in very elderly individuals, it is not a normal part of the aging process. The condition can also occur in children (see Childhood Dementia).
(Click Causes of Dementia for more information.)