What is Alzheimer's disease?

Alzheimer's disease is the most common type of dementia. About 6 in every 10 people with dementia have Alzheimer's disease.

Alzheimer's disease is a neurological condition (a condition affecting the brain) and can cause problems with your:

• memory
• thinking
• behaviour
• speech

Alzheimer's disease is progressive — this means that the effects of the disease will increase over time. It usually progresses over 8 to 10 years.

Alzheimer's disease is most common in people older than 65 years of age. Even though Alzheimer's disease is more common in older people, it's not a normal part of ageing.

What are the symptoms of Alzheimer's disease?

The symptoms of Alzheimer's disease depend on the stage of the disease.

Mild Alzheimer's disease

Early on, Alzheimer's disease may be hard to notice. The first symptoms are usually trouble remembering recent events and difficulty finding the right words for everyday things.

Other symptoms of mild Alzheimer's disease include:

• showing less emotion
• losing interest in hobbies or usual activities
• finding it hard to adapt to change
• becoming slower to understand complex ideas
• taking longer to finish normal tasks
• having trouble sleeping
• being disoriented (confused about where you are and what time it is)

Moderate Alzheimer's disease

If you have moderate Alzheimer's disease, the symptoms are often easier to notice and you may need help with daily tasks.

If you have moderate Alzheimer's disease, you might forget:

• recent events
• the names of your friends or family members
• where objects are or where you put them

You might also:

• repeat things
• have trouble planning or solving problems

Advanced Alzheimer's disease

Advanced Alzheimer's disease is the final stage. You will likely need help for all daily activities.

If you have late-stage Alzheimer's disease, you might:

• forget important information, such as where you live
• not be able to recognise people — even close family members
• become restless
• become incontinent (unable to control bladder or bowel movements)
• have difficulty walking

Alzheimer's disease causes change in your brain that might make it seem like your personality has changed. You might:

• be moody
• have trouble talking
• have delusions or hallucinations (such as hearing or seeing things that don't exist)
• become aggressive

People with Alzheimer's disease may also experience sundowning. This is when symptoms get worse towards the end of the day, causing:

• restlessness
• confusion
• suspicion

The symptoms of Alzheimer's disease usually start to appear in people over 65 years of age. Familial Alzheimer's disease, also known as 'younger onset dementia', can cause symptoms in people in their 50s. This is a very rare type of Alzheimer's disease caused by a genetic condition.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes Alzheimer's disease?

Your brain contains millions of neurons (brain cells) that pass signals using chemicals called neurotransmitters. These signals are how your brain:

• stores memories
• learns habits
• shapes your personality

In people with Alzheimer's disease, a build-up of certain proteins affects how well neurons pass signals.

These proteins are:

• amyloid proteins — when amyloid proteins build-up they form plaques. Plaques stick to the outside of your neurons.
• tau proteins — when tau proteins build-up they form tangles. Tangles form inside your neurons.

A build-up of these proteins causes damage to your neurons, which stops them from passing signals properly. The neurons eventually die, which causes shrinking of your cortex (the outer layer of the brain). The cortex is very important to your:

• memory
• language
• judgement

Scientists are unsure what causes the plaques and tangles in Alzheimer's disease.

Researchers have identified several genes that increase your chance of developing Alzheimer's disease.

When should I see my doctor?

See your doctor if you have any symptoms of Alzheimer's disease or are worried about your memory.

Diagnosing Alzheimer's disease early means your doctor can help you manage the condition. Early management can help with your symptoms and slow down the disease.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is Alzheimer's disease diagnosed?

There is no single test that can confirm Alzheimer's disease.

To diagnose Alzheimer's disease, your doctor will talk with you about:

• your medical history
• what changes you have noticed
• how these changes are affecting your life

Your doctor may also want to:

• do a full physical examination
• talk to people close to you to see what changes they have noticed

Your doctor might refer you to a specialist, such as a geriatrician or neuropsychologist. They can test your:

• thinking
• memory
• language
• problem-solving

They may arrange for you to have further testing, such as:

• urine tests
• blood tests
• a magnetic resonance imaging (MRI) scan of your brain
• a computed tomography (CT) scan of your brain
• a positron emission tomography (PET) scan of your brain
• a cerebrospinal fluid (CSF) test (a test that collects fluid from your spinal cord)

Read more about the tests used in diagnosing dementia.

If you have Alzheimer's disease, an early diagnosis allows you to plan for your future. You can start to talk about the medical treatment and further help you will need.

Learn about the different ways you can manage your life if you are diagnosed with dementia.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is Alzheimer's disease treated?

Although there is no cure for Alzheimer's disease, there are treatments that can help improve your symptoms and slow down the disease.

Medicines

A group of medicines called cholinesterase inhibitors can help signals pass between your neurons. This may help improve your memory and your ability to carry out day-to-day activities. Memantine is another type of medicine that blocks glutamate (a brain chemical) to help slow down Alzheimer's disease.

Other medicines, such as lecanemab and donanemab, can help prevent plaques and tangles forming. This can help slow down the disease. These medicines are expensive, not used very often and may not be helpful for everyone.

You may also be given other medicines to help ease symptoms, such as:

• sleeplessness
• agitation
• anxiety
• depression

These medicines don't treat Alzheimer's disease but can help improve your symptoms and quality of life.

Researchers are looking for ways to cure Alzheimer's disease.

Lifestyle changes

There are other things that you can do to improve your quality of life. Where possible, you should try to:

• take care of any other health conditions you have
• maintain normal contact with your friends and family
• exercise regularly
• eat a balanced diet

If you are worried about your safety, talk to your doctor. They can check if it is still safe for you to drive. As Alzheimer's disease gets worse, you will need to stop driving.

Creating a dementia-friendly home

If you care for someone with Alzheimer's disease, it may be helpful to make changes to their home environment.

For example, you could add clear instructions on how to open doors. This may help them feel less disoriented in daily life.

An occupational therapist (OT) can do a home safety evaluation. This can help identify ways to make the home safer and easier to use.

What are some complications of Alzheimer's disease?

Alzheimer's disease is a progressive disease — this means that the symptoms get worse over time. How quickly this happens can be different for each person.

Complications of Alzheimer's disease may include:

• being unable to do daily tasks, such as planning meals and managing money
• wandering away from home
• personality changes that make relationships more difficult
• delusions and hallucinations in advanced stages of the disease
• insomnia (difficulty getting to sleep or staying asleep)

If you have Alzheimer's disease, you may have a higher chance of:

• aspiration pneumonia (lung infection from inhaling food or fluid)
• urinary tract infections (UTIs)
• falls
• becoming isolated

People with Alzheimer's disease eventually need full time care and support.

Some people may have Alzheimer's disease only during the last 5 years of their life. Other people may have it for up to 20 years.

Can you prevent Alzheimer's disease?

Some types of Alzheimer's disease are due to factors that can't be changed, such as genetics and family history.

However, there are ways you can lower your chance of developing Alzheimer's disease. This includes:

• avoiding head injuries by wearing protective gear when playing sports
• having a healthy diet and maintaining a healthy weight
• stopping smoking
• reducing how much alcohol you drink
• keeping physically active

Other things you can do to lower your chances are:

• having regular contact with friends or family
• avoiding air pollution where possible
• keeping your brain active

It's also important to manage any conditions you have, including:

• depression
• hypertension (high blood pressure)
• diabetes
• high cholesterol
• hearing loss
• vision loss

There is not enough evidence to show that Alzheimer's disease can be prevented by:

• medicines
• over-the-counter supplements

Caring for someone with Alzheimer's disease

Caring for someone with Alzheimer's disease can be hard — but also rewarding. In the early stage of the illness, very little help may be needed. As Alzheimer's disease progresses, care needs will increase.

Here are some things that may help:

• Plan ahead — it's wise to plan for the future. Arrange for a trusted person to take care of your loved one's affairs. This is called a power of attorney.
• Write a care plan — it can help to support your loved one to write an Advanced Care Plan. This details the healthcare they want as their dementia gets worse.
• Care for yourself — it's important to take breaks from your caring role to look after your own needs. Learn more about the support available for carers on the My Aged Care page.

If someone you know has been diagnosed with dementia, they might be eligible for support from the Australian government through:

• the National Disability Insurance Scheme (NDIS), if they are younger than 65 years of age. Learn more about how to apply on the NDIS page.
• the National Dementia Support Program (NDSP). Learn more about the NDSP on the Department of Health, Disability and Ageing page.

Resources and support

Visit the Dementia Australia for information on:

• genetics and dementia
• what to expect after a diagnosis of Alzheimer's disease
• planning ahead if you have dementia
• younger onset dementia
• NDIS support for people living with dementia

You can also call Dementia Australia on 1800 100 500 to speak to an experienced counsellor. They support people living with dementia as well as their families, friends and carers.

Dementia Support Australia has a helpline that you can call on 1800 699 799. They offer advice and support to family, friends and carers of people with dementia.

Visit My Aged Care to find out about government-funded residential respite care (short term care) or the Support at Home program.

Languages other than English

‘It's Not a Disgrace... It's Dementia' is a series of 12 short films by Dementia Australia. They discuss how dementia affects people from different cultures.

Mindcare Collective has videos in multiple languages, including topics on:

• what is dementia
• how to reduce your dementia risk

Health Translations Victoria has fact sheets on dementia for patients and carers in languages other than English.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.