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Diagnosis - Alzheimer's disease

It's best to see a GP if you're worried about your memory or are having problems with planning and organising.

If you're worried about someone else, encourage them to make an appointment and perhaps suggest going with them. It's often very helpful having a friend or family member there.

An accurate, timely diagnosis gives you the best chance to adjust, prepare and plan for the future, as well as access to treatments and support that may help.

Seeing a GP

Memory problems are not just caused by dementia – they can also be caused by:

  • depression or anxiety
  • stress
  • medicines
  • alcohol or drugs
  • other health problems – such as hormonal disturbances or nutritional deficiencies

Read about common causes of memory loss.

A GP can carry out some simple checks to try to find out what the cause may be. They can then refer you to a specialist for assessment, if necessary.

A GP will ask about your concerns and what you or your family have noticed.

They'll also check other aspects of your health and carry out a physical examination.

They may also organise some blood tests and ask about any medicines you're taking to rule out other possible causes of your symptoms.

You'll usually be asked some questions and to carry out some memory, thinking, and pen and paper tasks to check how different areas of your brain are functioning.

This can help a GP decide if you need to be referred to a specialist for more assessments.

Referral to a specialist

If a GP is unsure about whether you have Alzheimer's disease, they may refer you to a specialist, such as:

  • a psychiatrist (usually called an old age psychiatrist)
  • an elderly care physician (sometimes called a geriatrician)
  • a neurologist (an expert in treating conditions that affect the brain and nervous system)

The specialist may be based in a memory clinic alongside other professionals who are experts in diagnosing, caring for and advising people with dementia and their families.

There's no simple and reliable test for diagnosing Alzheimer's disease, but the staff at the memory clinic will listen to the concerns of both you and your family about your memory or thinking.

They'll assess your memory and other areas of mental ability and, if necessary, arrange more tests to rule out other conditions.

Mental ability tests 

A specialist will usually assess your mental abilities, such as memory or thinking, using tests known as cognitive assessments.

Most cognitive assessments involve a series of pen and paper tests and questions, each of which carries a score.

These tests assess a number of different mental abilities, including:

  • short- and long-term memory
  • concentration and attention span
  • language and communication skills
  • awareness of time and place (orientation)
  • abilities related to vision (visuospatial abilities)

It's important to remember that test scores may be influenced by a person's level of education.

For example, someone who cannot read or write very well may have a lower score, but they may not have Alzheimer's disease.

Similarly, someone with a higher level of education may achieve a higher score, but still have dementia.

These tests can therefore help doctors work out what's happening, but they should never be used by themselves to diagnose dementia.

Other tests

To rule out other possible causes of your symptoms and look for possible signs of damage caused by Alzheimer's disease, your specialist may recommend having a brain scan.

This could be a:

  • CT scan – several X-rays of your brain are taken at slightly different angles and a computer puts the images together
  • MRI scan – a strong magnetic field and radio waves are used to produce detailed images of your brain

Read more about tests for diagnosing dementia.

After diagnosis

It may take several appointments and tests over many months before a diagnosis of Alzheimer's disease can be confirmed, although often it may be diagnosed more quickly than this.

It takes time to adapt to a diagnosis of dementia, for both you and your family.

Some people find it helpful to seek information and plan for the future, but others may need a longer period to process the news.

It might help to talk things through with family and friends, and to seek support from the Alzheimer's Society.

As Alzheimer's disease is a progressive illness, the weeks to months after a diagnosis are often a good time to think about legal, financial and healthcare matters for the future.

Read more about what to do if you have just been diagnosed with dementia.

Page last reviewed: 05 July 2021
Next review due: 05 July 2024