Alzheimer's disease

  • Alzheimer’s disease is the most common form of dementia.
  • Alzheimer’s disease is a physical brain condition resulting in impaired memory, thinking and behaviour.
  • It disrupts the brain’s neurons, affecting how they work and communicate with each other. A decrease of important chemicals stops messages travelling normally through the brain.
  • People with Alzheimer’s disease experience different challenges and changes throughout the progression of the condition.
  • An individual’s abilities deteriorate over time, although the progression varies from person to person.

Who gets Alzheimer’s disease

Anyone can develop Alzheimer’s disease, but it is more common in older age.

Genetics, lifestyle and health factors are associated with an increased risk of developing dementia.

In a few cases, Alzheimer’s disease is inherited, caused by a genetic mutation. This is called familial Alzheimer’s disease, with symptoms occurring at a relatively young age. This is usually when someone is in their 50s, but sometimes younger.

What causes Alzheimer’s disease

Apart from the few people with familial Alzheimer’s disease, it is not known why some people develop Alzheimer’s disease and others do not.

Health and lifestyle factors that may contribute to the development of Alzheimer’s disease include:

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

About the brain

The brain helps us to:

  • plan and organise things
  • make decisions
  • understand information
  • solve complex problems and do calculations
  • pay attention
  • behave properly
  • remember things
  • see, hear, taste, smell and feel
  • read and write
  • recognise people and objects
  • find our way
  • breathe
  • control our body temperature.

Signs and symptoms of Alzheimer’s disease

Symptoms may include:

  • persistent and frequent short-term memory loss, especially recalling more recent events
  • repeatedly saying the same thing
  • vagueness in everyday conversation
  • changes in ability to plan, problem solve, organise and think logically
  • taking longer to do routine tasks
  • language and comprehension difficulties, such as problems finding the right word
  • increasing disorientation in time, place and person
  • problems in becoming motivated and initiating tasks
  • changes in behaviour, personality and mood.

Someone experiencing symptoms may be unable to recognise any changes in themselves. Often a family member or friend of someone affected will observe changes in a person.

Symptoms vary as the condition progresses and as different areas of the brain are affected. A person’s abilities may fluctuate from day to day, or even within the same day. Symptoms can worsen in times of stress, fatigue or ill-health.

Diagnosing Alzheimer’s disease

Currently there is no single test to diagnose Alzheimer’s disease. A diagnosis is made after careful clinical consultation.

The assessment might include:

  • a detailed medical history
  • a physical examination
  • blood and urine tests
  • a psychiatric assessment
  • neuropsychological tests (to assess memory and thinking abilities)
  • brain scans.

After eliminating other causes, a diagnosis of Alzheimer’s disease can be made.

It is important to have an early and accurate diagnosis to determine whether symptoms being investigated are being caused by Alzheimer’s disease, or by a different condition requiring its own specific treatment.

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

How Alzheimer’s disease progresses

An individual’s abilities deteriorate over time, although the progression varies from person to person.

As Alzheimer’s disease affects different areas of the brain, specific functions or abilities are lost. Short-term memory is often the first to be affected, but as the disease progresses, long-term memory is also lost. The disease also affects many of the brain’s other functions and consequently language, attention, judgement and many other aspects of behaviour are affected.

Some abilities remain, although these lessen as Alzheimer’s disease progresses. People living with advancing dementia 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.

Stages of Alzheimer’s disease

Some features of Alzheimer’s disease are commonly classified into three stages, or phases. Not all these features will be present in every person, and they might occur at different stages.

Mild Alzheimer’s disease

Sometimes this stage is only apparent in hindsight. The onset of Alzheimer’s disease is usually gradual and it is often impossible to identify exactly when it began.

Someone 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 and take longer with routine jobs
  • become more forgetful of recent events
  • become confused or disoriented to time and place
  • become lost if away from familiar surroundings
  • be more likely to repeat him/herself or lose the thread of their conversation
  • be more irritable or upset if a mistake is made
  • have difficulty managing finances
  • have difficulty shopping or preparing meals.

Moderate Alzheimer’s disease

At this stage, the impacts of the condition are more apparent and prevalent. A person may experience significant challenges to their independence and require daily support.

Someone might:

  • be forgetful of current and recent events, although generally remember the distant past, even if details may be forgotten or confused
  • often be confused regarding time and place
  • become lost more easily
  • forget the names of family or friends, or confuse family members
  • forget saucepans or kettles left heating on the stove
  • be less able to perform simple calculations
  • show poor judgement and make poor decisions
  • see or hear things that are not there or become suspicious of others
  • become repetitive
  • neglect personal hygiene or eating
  • be unable to choose appropriate clothing for the weather, occasion or time of day
  • become angry, upset or distressed through frustration.

Advanced Alzheimer’s disease

At this stage, the person is severely impacted by dementia and needs continuous care for all daily activities.

Someone might:

  • be unable to remember current or recent events, such as forgetting that they have just eaten, or being unable to recall where they live
  • be unable to recall important events or facts from their early life
  • be confused trying to recognise friends and family
  • fail to recognise everyday objects or understand their purpose
  • lose their ability to understand, or to speak
  • need help eating, washing, bathing, brushing their teeth, toileting and dressing
  • become incontinent
  • experience disturbed sleep
  • be restless or fidgety
  • call out frequently or have aggressive outbursts
  • have difficulty walking and other movement problems, including rigidity.

Treatment and management options

At present there is no cure for Alzheimer’s disease and no treatment can stop the condition progressing. However, medications can help stabilise or slow the decline in memory and thinking abilities. Drugs may also be prescribed for secondary symptoms such as agitation or depression, or to improve sleep. Non-drug therapies can be beneficial, such as staying active and socially connected, and managing stress.

Talking to a counsellor or psychologist is important to help manage changes in behaviour and mood.

Occupational therapy can help improve everyday functioning at home.

At all stages of Alzheimer’s disease, treatments and support services are available to reduce the impact of symptoms, to ensure the best possible quality of life for every person living with the condition.

Seeking Support

Education about the disease and professional support are important for the person living with dementia, their family and carers. This support can make a positive difference to managing the condition.

A range of approaches and activities can engage the abilities and interests of the person living with dementia, to live well for as long as possible.

Further help