Skip to main content

Alzheimer's disease

Key points

  • The most common form of dementia, Alzheimer’s disease is a physical brain condition resulting in impaired memory, thinking and behaviour, where a person’s abilities deteriorate over time.

  • Anyone can get Alzheimer’s disease, although it’s more common in older people.

  • There is no cure for Alzheimer’s disease, but the condition can be managed and some symptoms can be treated. Support is available.

What is Alzheimer's disease?

About Alzheimer’s disease

Alzheimer’s disease is the most common form of dementia.

Alzheimer’s disease causes damage to your neurons – cells in your brain that carry messages. Just like plaque grows on your teeth, a plaque of proteins forms on your neurons. Other proteins tangle up inside the neurons.

These damaged neurons can’t communicate with each other as well as they used to. The neurons eventually die and your brain’s volume shrinks.

If you have Alzheimer’s disease, you might experience memory loss, slower thinking and changed behaviour. These changes can happen in different ways and at different speeds for each person.

Over time, as Alzheimer’s disease develops, your memory, thinking and behaviour will become more affected.

There is no known cure for Alzheimer’s disease. But there is medication, treatment and support to help you live the best life you can.

Causes of Alzheimer’s disease

Anyone can develop Alzheimer’s disease, but it becomes more common as you get older. In people younger than 65, it’s called younger-onset Alzheimer’s disease.

Currently, we don’t understand well why some people develop Alzheimer’s disease and others don’t.

However, you’re more likely to develop Alzheimer’s disease if you have a history of:

  • physical inactivity
  • lack of mental exercise
  • smoking
  • obesity
  • diabetes
  • high cholesterol
  • high blood pressure.

Staying healthy can reduce your risk of developing Alzheimer’s disease.

Other people more likely to develop Alzheimer’s disease include:

Familial Alzheimer’s disease

A very small number of people inherit Alzheimer’s disease from their biological parents. People with familial Alzheimer’s disease often start getting symptoms in their 50s, sometimes younger.

Aboriginal people

Aboriginal people are more likely to develop Alzheimer’s disease than non-Aboriginal Australians and possibly at an earlier age.

People with Down syndrome

People with Down syndrome have a much higher chance of developing Alzheimer’s disease, and at a much earlier age, than other people. Around half of people with Down syndrome will develop Alzheimer’s disease by age 60. Many people with Down syndrome start experiencing symptoms in their early to mid-50s.

Read more about Down syndrome and Alzheimer’s disease.


About a quarter of all Australians have a gene in their DNA that gives them a slightly increased risk of developing Alzheimer’s disease. Even so, half the people with that gene live to be 85 without developing Alzheimer’s disease.

Signs and symptoms of Alzheimer’s disease

Someone with Alzheimer’s disease may experience:

  • trouble remembering, especially recent events
  • repeatedly saying the same thing
  • being vague in everyday conversation
  • trouble planning, solving problems, organising and thinking logically
  • taking longer to do everyday tasks
  • language difficulties, such as problems finding the right word
  • trouble remembering the time, where you are and who people are
  • trouble becoming motivated and starting tasks
  • unusual changes in behaviour, personality and mood.

Someone with these symptoms might not be able to recognise their own changes. Often a family member or friend will notice them instead.

If you have any of these symptoms, or if you know someone else who does, talk to your doctor. They might find another cause for the changes that they can treat, or begin treating and help you manage Alzheimer’s disease in its early stages.

Diagnosing Alzheimer’s disease

Currently there is no single test to tell if a person has Alzheimer’s disease.

A medical specialist will only make a diagnosis of Alzheimer’s disease after careful assessment. This might include:

  • a detailed medical history
  • a physical examination
  • blood and urine tests
  • a psychiatric assessment
  • memory and thinking tests
  • brain scans.

If the medical specialist can rule out any other causes, they may diagnose the person with Alzheimer’s disease.

New techniques are becoming available to help diagnose Alzheimer’s disease, even before symptoms begin.

The progression of Alzheimer’s disease

Everyone’s experience of Alzheimer’s disease is unique. However, there are some things everyone with Alzheimer’s disease will experience.

Over time, Alzheimer’s disease affects different areas of the brain, damaging different abilities. Short-term memory is often affected first, but later, long-term memory is also affected. The disease also affects language, attention, judgement and many other aspects of behaviour over time.

People living with Alzheimer’s disease may keep their senses of touch and hearing, and also respond to emotion, even in the advanced stages of the condition.

At the end stages of Alzheimer’s disease many people become immobile and dependent, requiring extensive care.

Alzheimer’s disease has three stages: mild, moderate and advanced. They’re not exactly the same for everyone, and they may happen more slowly or quickly for different people.

Mild Alzheimer’s disease

Mild Alzheimer’s disease is the earliest stage. Because these changes usually happen gradually, it’s sometimes hard to notice when this stage begins. Many people get their diagnosis of Alzheimer’s disease after this stage.

If you have mild Alzheimer’s disease, you might:

  • appear more apathetic
  • lose interest in hobbies and activities
  • be less willing to try new things
  • be less able to adapt to change
  • be slower to grasp complex ideas
  • take longer with routine jobs
  • have disturbed sleep
  • become more forgetful of recent events
  • become confused about time and place
  • become lost if you’re away from familiar surroundings
  • be more likely to repeat yourself or get lost in conversation
  • be more upset if a mistake is made
  • have trouble managing money
  • have trouble shopping or preparing meals.

Moderate Alzheimer’s disease

Moderate Alzheimer’s disease is the next stage of the disease. Your symptoms will become stronger. You may experience significant challenges to your independence. You might require daily support.

If you have moderate Alzheimer’s disease, you might:

  • become angry, upset or distressed through frustration
  • become lost more easily
  • become repetitive
  • forget recent events
  • remember the distant past better, sometimes with confused details
  • be less able to perform simple maths
  • be unable to choose the right clothing
  • forget saucepans or kettles on the stove
  • forget the names of your family or friends, or mix-up family members
  • neglect your personal hygiene
  • have increasingly disturbed sleep
  • forget to eat
  • get confused about time and place
  • see or hear things that are not there
  • become suspicious of other people
  • make poor decisions.

Advanced Alzheimer’s disease

Advanced Alzheimer’s disease is the final stage. Your symptoms will become severe, and you will need care for all your daily activities.

If you have advanced Alzheimer’s disease, you might:

  • become incontinent
  • get confused trying to recognise friends and family
  • be restless or fidgety
  • forget important events from your early life
  • forget current events and information, like where you live
  • call out frequently or behave out of character
  • have increasingly disturbed sleep
  • stop recognising everyday objects and what they’re for
  • have difficulty walking
  • lose your ability to understand or speak
  • need help eating, washing, bathing, brushing your teeth, going to the toilet and dressing.

In the last stages of Alzheimer’s disease, you are likely to become immobile and require constant care. How fast this happens is different for everyone, but the average is seven to 10 years. However, Alzheimer’s disease will eventually lead to complete dependence and, finally, death.

Treatment and management of Alzheimer’s disease

Right now, there’s no known cure for Alzheimer’s disease.

However, there are treatments and support services help to ensure your best possible quality of life as you live with the condition.

Your doctor may prescribe medications that may help slow the decline in your memory and thinking, so you can think more clearly for longer. They may also prescribe medicines for other conditions, like restlessness or depression, or to help you sleep better.

Staying physically active and socially connected, and managing stress, can also be beneficial in helping you live well for as long as possible. Talk to your doctor about the best options for you.

Talking to a counsellor or psychologist can help you manage the changes in your behaviour and mood.

Occupational therapy can help you to function well at home.

How Dementia Australia can help

Whatever your experience of dementia, we're here for you.

Share or print
Last updated
24 November 2023