What is dementia?

We answer some common questions about dementia.

In Australia, dementia affects approximately one person in 10 aged over 65 years, and more than half of people over 80. 

What is dementia?

Dementia is an umbrella term (like the word cancer) that is used to describe a number of symptoms that are caused by irreversible and ongoing deterioration of the brain. 

What are the main types of dementia?

There are more than 100 different types of dementia. An individual may have a combination of different types of dementia, such as Alzheimer’s disease and vascular dementia.

The most common dementia types are: 
  • Alzheimer’s disease

    This is the most common form of dementia. It is caused by damage to the nerve cells in the brain and results in forgetfulness, trouble with speech and difficulty with everyday tasks.

  • Vascular dementia

    This is the second most common form of dementia. It is caused by tiny strokes in the brain and affects behaviour, speech and functioning. 

  • Dementia with Lewy bodies

    This type of dementia is caused by tiny protein deposits (Lewy bodies) being present in the nerve cells in the brain. They disrupt normal brain function, causing difficulties with memory, language and reasoning.

What are the symptoms of dementia?

All types of dementia have similar symptoms , but these are some of the main ones to look out for:
  • Memory loss.
  • Misplacing things.
  • Difficulty remembering simple words.
  • Difficulty performing everyday tasks.
  • Becoming disorientated easily.
  • Change in mood or behaviour.
  • Becoming withdrawn and depressed.
It’s important to remember that these symptoms don’t necessarily mean your loved one has dementia; they could be symptoms of being run-down, or of other conditions such as depression. This means it’s particularly important to speak to your doctor if you are concerned. 
Man talking to doctor

What should I do if I think a loved one has dementia?

If you are concerned about a loved one or even yourself, it’s important to speak to a doctor as soon as possible. 

How is dementia diagnosed? 

Your doctor will look at your loved one’s medical history and carry out some tests , such as blood and urine tests, to make sure their symptoms aren’t caused by another condition. 

After these tests, the doctor may refer your loved one to a specialist for further tests such as:
  • Cognitive tests to measure memory, language and concentration.
  • Brain scans (computed tomography [CT] or magnetic resonance imaging [MRI]) to investigate possible brain damage. 
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