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What is Dementia?

Dementia is a general term for a decline in mental ability severe enough to interfere with daily life. It is not a specific disease, but an overall term that describes a wide range of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person's ability to perform everyday activities.


What are the symptoms of dementia?

While symptoms of dementia can vary, at least two of the following care mental functions must be significantly impaired to be considered dementia:

  • Memory
  • Communication and language
  • Ability to focus and pay attention
  • Reasoning and judgment
  • Visual perception


What are the causes of dementia?

Dementia is caused by damage to the brain cells which interferes with the ability of the brain cells to communicate with each other. When brain cells cannot communicate normally, thinking, behavior, and feelings can be affected. 

Different types of dementia are associated with particular types of brain cell damage in particular regions of the brain. For example, in Alzheimer's disease, high levels of certain proteins inside and outside brain cells make it hard for brain cells to stay healthy and to communicate with each other. The brain region called the hippocampus is the center of learning and memory in the brain, and the brain cells in this region are often the first to be damaged. That's why memory loss is often one of the earliest symptoms of Alzheimer's.

Most changes in the brain that cause dementia are permanent and worsen over time, thinking and memory problems caused by the following conditions may improve when the condition is treated or addressed:

  • Depression
  • Medication side effects
  • Excess use of alcohol
  • Thyroid problems
  • Vitamin deficiencies


How is dementia diagnosed?

There is not an exclusive test to determine if someone has dementia. Physicians diagnose types of dementia based on a careful medical history, a physical examination, lab tests, and the characteristic changes in thinking, day-to-day function and behavior associated with each type. Physicians can usually determine that a person has dementia with a high level of certainty, but it is harder to determine the exact type because the symptoms and brain changes of different dementias can overlap. In some cases, a physician may diagnose "dementia" and not specify a type.


How is dementia treated?

Treatment of dementia depends on its cause. In the case of most progressive dementias, there is not a cure and no treatment that slows or stops its progression. There are medications that may temporarily improve symptoms; consult your physician regarding these medications.


Are there ways to prevent dementia?

Some risk factors for dementia like age and genetics cannot be changed. The following could play a part in risk reduction of dementia:

  • Cardiovascular risk factors; your brain is nourished by one of your body's richest networks of blood vessels. Anything that damages blood vessels in your body can damage blood vessels in your brain, depriving brain cells of vital food and oxygen. Blood vessel changes in the brain are linked to vascular dementia and are often present along with changes caused by other types of dementia. These changes may interact to cause faster decline or make impairments more severe. You can help protect your brain with some of the same strategies that protect your heart. For example, do not smoke, take steps to keep your blood pressure, cholesterol, and blood sugar within recommended limits, and maintain a healthy weight. 
  • Physical exercise; regular physical exercise may help lower the risk of some types of dementia. Evidence suggests exercise may directly benefit brain cells by increasing blood and oxygen flow to the brain. 
  • Diet: what you eat may have its greatest impact on brain health through its effect on heart health. The best current evidence suggests that heart-healthy eating patterns may also help protect the brain.