Diagnosing dementia

What are the early signs of dementia and the techniques used to diagnose dementia and the importance of an early and correct diagnosis.

What are the early signs of dementia?

Because the diseases that cause dementia develop gradually, the early signs may be very subtle and vague, and not immediately obvious. Early symptoms also depend on the type of dementia and vary a great deal from person to person.

Common early symptoms include:

• Memory problems, particularly remembering recent events

• Increasing confusion

• Reduced concentration

• Personality or behaviour changes

• Apathy and withdrawal or depression

• Loss of ability to do everyday tasks

Sometimes people fail to recognise that these symptoms indicate that something is wrong. They may mistakenly assume that such behaviour is a normal part of ageing, or symptoms may develop so gradually they go unnoticed for a long time. Sometimes people may be reluctant to act even when they know something is wrong.

Warning signs

This is a checklist of common symptoms of dementia. Go through the list and tick any symptoms that are present. If there are several ticks, consult a doctor for a complete assessment.

Memory loss that affects day-to-day function
It’s normal to occasionally forget appointments and remember them later. A person with dementia may forget things more often or not remember them at all.

Difficulty performing familiar tasks
People can get distracted and they may forget to serve part of a meal. A person with dementia may have trouble with all the steps involved in preparing a meal. Disorientation to time and place A person with dementia may have difficulty finding their way to a familiar place, or feel confused about where they are, or think they are back in some past time of their life.

Problems with language
Everyone has trouble finding the right word sometimes, but a person with dementia may forget simple words or substitute inappropriate words, making them difficult to understand. They might also have trouble understanding others.

Problems with abstract thinking 
Managing finances can be difficult for anyone, but a person with dementia may have trouble knowing what the numbers mean or what to do with them.

Poor or decreased judgement
Many activities require good judgement. When this ability is affected by dementia, the person may have difficulty making appropriate decisions, such as what to wear in cold weather. Problems with spatial skills A person with dementia may have difficulty judging distance or direction when driving a car.

Problems misplacing things
Anyone can temporarily misplace a wallet or keys. A person with dementia may often put things in inappropriate places.

Changes in mood, personality or behaviour 
Everyone becomes sad or moody from time to time. Someone with dementia can exhibit rapid mood swings for no apparent reason. They can become confused, suspicious or withdrawn. Some can become disinhibited or more outgoing.

A loss of initiative
It’s normal to tire of some activities. However, dementia may cause a person to lose interest in previously enjoyed activities.

It may not be dementia

Remember that many conditions have symptoms similar to dementia, so do not assume that someone has dementia just because some of the above symptoms are present. Strokes, depression, alcoholism, infections, hormone disorders, nutritional deficiencies and brain tumours can all cause dementia-like symptoms. Many of these conditions can be treated.

A correct diagnosis is important

Consulting a doctor at an early stage is critical. Only a medical practitioner can diagnose dementia. A complete medical assessment may identify a treatable condition and ensure that it is treated correctly, or it might confirm the presence of dementia.

An assessment may include the following:

Medical history – the doctor will ask about past and current medical problems, family medical history, any medications being taken, and the problems with memory, thinking or behaviour that are causing concern. The doctor may also wish to speak to a close family member who can help provide all the necessary information.

Physical examination – this may include tests of the senses and movement function, as well as heart and lung function, to help rule out other conditions.

Laboratory tests – will include a variety of blood and urine tests to identify any possible illness which could be responsible for the symptoms. In some cases, a small sample of spinal fluid may be collected for testing.

Neuropsychological or cognitive testing – a variety of tests are used to assess thinking abilities including memory, language, attention and problem solving. This can help identify specific problem areas, which in turn helps identify the underlying cause or the type of dementia.

Brain imaging – There are certain scans that look at the structure of the brain and are used to rule out brain tumours or blood clots in the brain as the reason for symptoms, and to detect patterns of brain tissue loss that can differentiate between different types of dementia. Other scans look at how active certain parts of the brain are and can also help discriminate the type of dementia.

Psychiatric assessment – to identify treatable disorders such as depression, and to manage any psychiatric symptoms such as anxiety or delusions which may occur alongside dementia.

Where to begin?

The best place to start is with the person’s doctor. After considering the symptoms and ordering screening tests, the doctor may offer a preliminary diagnosis or refer the person to a medical specialist such as a neurologist, geriatrician or psychiatrist.

Some people may be resistant to the idea of visiting a doctor. Sometimes people are in denial or do not realise that there is anything wrong with them. This can be due to the brain changes of dementia that interfere with the ability to recognise or appreciate the changes occurring. Others, who do have insight into their condition, may be afraid of having their fears confirmed. One of the best ways to overcome this problem is to find another reason to visit the doctor. Perhaps suggest a blood pressure check or a review of a long-term condition or medication. Another way is to suggest that it is time for both of you to have a physical check-up. A calm attitude at this time can help overcome the person’s worries and fears.  

If the person still will not visit the doctor:

  • Talk with other families and carers who may have had to deal with similar situations
  • Talk to the person’s doctor for advice
  • Contact your local Aged Care Assessment Team (ACAT). Call 1800 200 422 for information.
  • Call the National Dementia Helpline on 1800 100 500


This fact sheet has been reproduced with kind permission from Alzheimer's Australia. For more information, please visit Alzheimer's Australia.