Alzheimer's disease is the most common type of dementia, affecting an estimated 850,000 people in the UK.

Dementia is a progressive neurological disease which affects multiple brain functions, including memory.

The exact cause of Alzheimer's disease is unknown, although a number of things are thought to increase your risk of developing the condition. These include:

It's becoming increasingly understood that it's very common to have both changes of Alzheimer's and vascular dementia together (mixed dementia).

Read more about the causes of Alzheimer's disease.

Signs and symptoms of Alzheimer's disease

Alzheimer's disease is a progressive condition, which means the symptoms develop gradually and become more severe over the course of several years. It affects multiple brain functions.

The first sign of Alzheimer's disease is usually minor memory problems. For example, this could be forgetting about recent conversations or events, and forgetting the names of places and objects.

As the condition develops, memory problems become more severe and further symptoms can develop, such as:

  • confusion, disorientation and getting lost in familiar places
  • difficulty planning or making decisions
  • problems with speech and language
  • problems moving around without assistance or performing self-care tasks
  • personality changes, such as becoming aggressive, demanding and suspicious of others
  • hallucinations (seeing or hearing things that aren't there) and delusions (believing things that are untrue)
  • low mood or anxiety

Read more about the symptoms of Alzheimer's disease.

Who is affected?

Alzheimer's disease is most common in people over the age of 65, and affects slightly more women than men.

The risk of Alzheimer's disease and other types of dementia increases with age, affecting an estimated 1 in 14 people over the age of 65 and 1 in every 6 people over the age of 80.

However, around 1 in every 20 cases of Alzheimer's disease affects people aged 40 to 65.

Receiving a diagnosis

As the symptoms of Alzheimer's disease progress slowly, it can be difficult to recognise that there's a problem. Many people feel that memory problems are simply a part of getting older.

However, a timely diagnosis of Alzheimer's disease can give you the best chance to prepare and plan for the future, as well as receive any treatment or support that may help.

If you're worried about your memory or think you may have dementia, it's a good idea to see your GP. If you're worried about someone else, you should encourage them to make an appointment and perhaps suggest that you go along with them.

There's no single test that can be used to diagnose Alzheimer's disease. Your GP will ask questions about any problems you are experiencing and may do some tests to rule out other conditions.

If Alzheimer's disease is suspected, you may be referred to a specialist memory service to:


  • discuss the process of making the diagnosis
  • organise testing 
  • create a treatment plan


Read more about diagnosing Alzheimer's disease.

How Alzheimer's disease is treated

There's no cure for Alzheimer's disease, but medication is available that can help relieve some of the symptoms and slow down the progression of the condition in some people.

Various other types of support are also available to help people with Alzheimer's live as independently as possible, such as making changes to your home environment so it's easier to move around and remember daily tasks.

Psychological treatments such as cognitive stimulation therapy may also be offered to help support your memory, problem solving skills and language ability.

Read more about treating Alzheimer's disease.


On average, people with Alzheimer's disease live for around 8 to 10 years after they start to develop symptoms. However, this can vary considerably from person to person. Some people with the condition will live longer than this, but others will not.

Alzheimer's disease is a life-limiting illness, although many people diagnosed with the condition will die from another cause.

As Alzheimer’s disease is a progressive neurological condition, it can cause problems with swallowing. This can lead to aspiration (food being inhaled into the lungs) which can cause frequent chest infections. It's also common for people with Alzheimer’s disease to eventually have difficulty eating and to have a reduced appetite. 

There's increasing awareness that people with Alzheimer’s disease need palliative care. This includes support for families, as well as the person with Alzheimer's.

Can Alzheimer's disease be prevented?

As the exact cause of Alzheimer's disease isn't clear, there's no known way to prevent the condition. However, there are things you can do that may reduce your risk or delay the onset of dementia, such as:

These measures have other health benefits, such as lowering your risk of cardiovascular disease and improving your overall mental health.

Read more about preventing Alzheimer's disease.

Page last reviewed: 17/03/2016

Next review due: 17/03/2018