Alzheimer Society of Toronto - What is Dementia?

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What is Dementia?

Dementia is a syndrome that causes a serious loss of cognitive ability, beyond that of normal aging. Symptoms of dementia include:

Loss of memory
Loss of judgment and reasoning
Changes in mood and behaviour

These symptoms may affect a person's ability to function at work, in social relationships or in day-to-day activities. Sometimes symptoms of dementia can be caused by conditions that may be treatable, such as depression, thyroid disease, infections or drug interactions. If the symptoms are not treatable and progress over time, they may be due to damage to the nerve cells in the brain.

Alzheimer's disease, the most common form of dementia, accounts for 64% of all dementias in Canada. The features of Alzheimer's disease include a gradual onset and continuing decline of memory, as well as changes in judgment or reasoning, and the inability to perform familiar tasks.

Sometimes a person may have symptoms such as sudden onset of memory loss, early behaviour changes, or difficulties with speech and movement. These symptoms may suggest a dementia other than Alzheimer's disease.

A person should seek a thorough medical assessment if any of the above symptoms are present.

Regardless of the dementia, individuals can obtain information and support from the Alzheimer Society.