Alzheimer’s Disease – A Guide

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Alzheimer’s disease is the most common form of dementia, which is a group of symptoms associated with a decline in mental abilities, such as memory and reasoning

See also: Dementia


Alzheimer’s disease attacks nerves, brain cells and neurotransmitters (chemicals that carry messages to and from the brain). Although Alzheimer’s disease is often associated with increasing age, the exact cause is unknown (see Alzheimer’s disease – causes).

Alzheimer’s disease is a progressive condition, which means that it will continue to get worse as it develops. Early symptoms include:

  • minor memory problems
  • difficulty saying the right words

These symptoms change as Alzheimer’s disease develops, and it may lead to:

  • confusion
  • personality changes
  • a total change in behaviour

See Alzheimer’s disease – symptoms for more information.

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How common is Alzheimer’s disease?

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

The Alzheimer’s Society estimates that, in people over 65 years of age, 1 in 14 is affected by Alzheimer’s disease. The risk increases with age, and people who are over 80 years of age are thought to have a one in six chance of developing the condition.

Dementia affects around 570,000 people in England, with Alzheimer’s disease responsible for around 60% of dementia cases. Dementia in people under 65 years of age, known as early-onset dementia, is less common. In the UK, around 2% of all dementia cases are early-onset dementia.


Although there is no cure for Alzheimer’s disease, medication is available that can slow down the development of the condition.

As with the treatment of any type of dementia, a care plan can be arranged to provide any necessary care and support for someone who is diagnosed with Alzheimer’s disease.

Symptoms of Alzheimer’s disease

Many of the symptoms of Alzheimer’s disease are similar to those of other conditions.

No two cases of Alzheimer’s disease are ever the same because different people react in different ways to the condition. However, generally, there are three stages to the condition:

  • mild
  • moderate
  • severe

Alzheimer’s disease tends to ‘creep up’ on you, so you may not notice the symptoms immediately. The symptoms progress slowly over a seven- to ten-year period. However, the rate at which they progress will differ for each individual.

The three stages of Alzheimer’s disease are described below.

Mild Alzheimer’s disease

Common symptoms of mild Alzheimer’s disease include:

  • confusion
  • poor memory and forgetfulness
  • mood swings
  • speech problems

These symptoms are a result of a gradual loss of brain function. The first section of the brain to start deteriorating is often the part that controls the memory and speech functions.

Moderate Alzheimer’s disease

As Alzheimer’s disease develops into the moderate stage, it can also cause:

  • hallucinations: where you hear or see things that are not there
  • delusions: where you believe things that are untrue
  • obsessive or repetitive behaviour
  • a belief that you have done or experienced something that never happened
  • disturbed sleep
  • incontinence: where you unintentionally pass urine (urinary incontinence) or stools (faecal or bowel incontinence)

During the moderate stage, you may have difficulty remembering very recent things. Problems with language and speech could also start to develop at this stage. This can make you feel frustrated and depressed, leading to mood swings.

Severe Alzheimer’s disease

Someone with severe Alzheimer’s disease may seem very disorientated and show signs of major confusion.

This is also the stage where people are most likely to experience hallucinations and delusions. They may think that they can smell, see or hear things that are not there, or believe that someone has stolen from them or attacked them when they have not. This can be distressing for friends and family, as well as for the person with Alzheimer’s disease.

The hallucinations and delusions are often worse at night, and the person with Alzheimer’s disease may start to become violent, demanding and suspicious of those around them.

As Alzheimer’s disease becomes severe, it can also cause a number of other symptoms such as:

  • difficulty swallowing
  • difficulty changing position or moving from place to place without assistance
  • weight loss or a loss of appetite
  • increased vulnerability to infection
  • complete loss of short-term and long-term memory

During the severe stage of Alzheimer’s disease, people often start to neglect their personal hygiene. It is at this stage that most people with the condition will need to have full-time care because they will be able to do very little on their own.

Life expectancy

Alzheimer’s disease affects a person’s ability to look after themselves when they are unwell, so another health condition can develop rapidly if left untreated. A person with Alzheimer’s may also be unable to tell someone if they feel unwell or uncomfortable.

Alzheimer’s disease can shorten life-expectancy. This is often caused by those affected developing another condition, such as pneumonia (inflammation of the lungs), as a result of having Alzheimer’s disease. In many cases, Alzheimer’s disease may not be the actual cause of death, but it can be a contributing factor.

Causes of Alzheimer’s disease

Alzheimer’s disease is caused by parts of the brain wasting away, which damages the structure of the brain and how it works. The medical name for wasting away is atrophy.

The atrophy mainly affects the cerebral cortex, which is the layer of grey matter that covers the brain. Grey matter is responsible for processing thoughts.

Plaques and tangles

As the cerebral cortex wastes away, clumps of protein, known as ‘plaques’ and ‘tangles’, start to form in the brain. The plaques and tangles start to destroy more brain cells, which makes the condition worse. They also affect the neurotransmitters (chemicals that carry messages to and from the brain).

Risk factors

It is still unknown what actually causes the deterioration of brain cells, although there are several factors that are known to affect the development of Alzheimer’s disease. These are described in more detail below.


Age is the greatest factor in the development of Alzheimer’s disease. The likelihood of developing the condition doubles every five years after you reach 65 years of age. However, it is not just older people who are at risk of developing Alzheimer’s disease.

Family history

Alzheimer’s disease can also be inherited (run in the family), although the risk is only marginally higher than that of someone who has no family history of the condition.

In cases where Alzheimer’s disease is inherited, the symptoms may start to develop at a relatively early age (between 35 and 60 years of age).

Down’s syndrome

People with own’s syndrome(a genetic disorder that affects physical appearance, as well as the ability to learn and develop mentally) are at a higher risk of developing Alzheimer’s disease.

This is because people with Down’s syndrome have an extra copy of chromosome 21, which contains a protein found in the brain of those with Alzheimer’s disease. Therefore, people with Down’s syndrome have a higher-than-average amount of this protein, which could contribute to developing Alzheimer’s disease.

Whiplash and head injuries

People who have had a severe head injury, or severe whiplash (a neck injury caused by a sudden movement of the head forwards, backwards or sideways), have been found to have a higher risk of developing Alzheimer’s disease.


Aluminium is a naturally occurring substance found in food and plants. It is also added to products, such as pans, packaging and medicines. The body only absorbs a minimal amount of aluminium, which is usually passed out of the body in urine.

It has been suggested that aluminium could be a possible cause of Alzheimer’s disease because research found that the plaques and tangles in the brain contain aluminium. However, further research has failed to prove a link between aluminium and Alzheimer’s disease.

Diagnosing Alzheimer’s disease

You should visit your GP if you think that you may have Alzheimer’s disease. They will want to know about any new or worsening problems that you have noticed. For example:

  • forgetfulness
  • not understanding what people say
  • changes in your behaviour
  • difficulty with everyday activities

Similar conditions

Alzheimer’s disease can be a difficult condition to diagnose because the symptoms can be similar to those of other health conditions. For example, the symptoms of Alzheimer’s disease may be confused with:

  • a vitamin deficiency: where there is not enough of one of the vitamins that your body needs to function
  • thyroid problems: your thyroid gland is in your neck and produces hormones (powerful chemicals)
  • an infection
  • anxiety
  • a brain tumour: a growth of cells in your brain
  • depression


There is no basic test for diagnosing Alzheimer’s disease, so the diagnosis is usually based on ruling out other conditions. You may have blood tests and a physical examination to rule out other medical conditions that could be causing your symptoms.

If your GP suspects Alzheimer’s disease, you may also be given a brain scan, which will look for changes in your brain. This could be:

  • a computed tomography (CT) scan: where several X-rays of your brain are taken at slightly different angles, and a computer is used to put the images together
  • a magnetic resonance imaging (MRI) scan: where a strong magnetic field and radio waves are used to produce detailed images of the inside of your brain

See Dementia – diagnosis for more information about the different tests that you might have.


Your GP may refer you to a specialist to help with the diagnosis. For example, you may be referred to:

  • a clinical psychologist: a healthcare professional who specialises in the assessment and treatment of mental health conditions
  • a psychiatrist: a qualified medical doctor who has further training in treating mental health conditions
  • a neurologist: a specialist in treating conditions that affect the nervous system (the brain and spinal cord)

Your specialist may carry out some tests to assess your memory and thinking skills. One example is explained below.

Mini Mental State Examination (MMSE)

The Mini Mental State Examination (MMSE) is a test that is sometimes used to assess the severity of Alzheimer’s disease. MMSE cannot provide a diagnosis of Alzheimer’s disease on its own, but it may help determine the treatment you should receive.

MMSE can be used to assess a number of different mental abilities including:

  • short- and long-term memory
  • attention span
  • concentration
  • language and communication skills
  • ability to plan
  • ability to understand instructions

The MMSE test consists of a series of tasks such as:

  • memorising a short list of objects and then repeating the list back
  • writing a short sentence that is grammatically correct, such as ‘the dog sat on the floor’
  • correctly indentifying the current day of the week, followed by the date, the month, the season and the year

The maximum score for the MMSE is 30. A score of 30 is classed as normal, but any less than 30 and you may have Alzheimer’s disease. The lower your score, the more severe your condition is. Alzheimer’s disease is classified as follows:

  • mild: MMSE score of between 21 and 26
  • moderate: MMSE score of between 10 and 20
  • moderately severe: MMSE score of between 10 and 14
  • severe: MMSE score of less than 10

MMSE might not be the most suitable way of assessing the severity of your Alzheimer’s disease, in which case it may not be used, or it may be used alongside other tests. Factors that may affect your MMSE score will be taken into consideration, for example:

  • if you have learning difficulties
  • if the test is not available in a language that you can speak fluently

Confirmed diagnosis

It may take several appointments with your GP and specialist before a diagnosis of Alzheimer’s disease can be confirmed.

If you are diagnosed with Alzheimer’s disease, your GP or specialist may recommend that the diagnosis is shared with your family or your carers. However, this will only be done with your permission.

Treating Alzheimer’s disease

There is currently no cure for Alzheimer’s disease, but there are various medications that are available on prescription that can help delay the condition’s development.

Treatment for Alzheimer’s disease also involves creating a care plan. This identifies the type of assistance that you might need, and focuses on ways of providing this support.


Medication that may be prescribed for Alzheimer’s disease includes:

  • donepezil (brand name Aricept)
  • rivastigmine (brand name Exelon)
  • galantamine (brand name Reminyl)
  • memantine (brand name Ebixa)

Whether these medications are used will depend on the severity of your Alzheimer’s disease. This will be assessed with tests, such as the Mini Mental State Examination (MMSE). See Alzheimer’s disease – diagnosis for an explanation of the MMSE.

In the first instance, these medications can only be prescribed by a specialist who has experience in treating dementia, such as:

  • a psychiatrist: a qualified medical doctor who has further training in treating mental health conditions
  • a neurologist: a specialist in treating conditions that affect the nervous system (the brain and spinal cord)
  • a physician (medical doctor) who specialises in care for the elderly

After this, your GP may be able to repeat your prescription, and you may be monitored by both your specialist and your GP. Your MMSE score will be reviewed every six months.

Moderate Alzheimer’s disease

If you have moderate Alzheimer’s disease (if your MMSE score is between 10 and 20), the National Institute for Health and Clinical Excellence (NICE) recommends that you are prescribed:

  • donepezil
  • galantamine
  • rivastigmine

The healthcare professionals treating you will decide which of these medicines is the most appropriate treatment for you.

Donepezil, galantamine and rivastigmine are known as acetylcholinesterase inhibitors. They work by preventing a chemical breakdown in the brain.

When nerve cells are damaged by brain deterioration they release a chemical called acetylcholine. By preventing the breakdown of acetylcholine, brain deterioration is also slowed.

Severe Alzheimer’s disease

In the UK, memantine is licensed to treat people with moderate to severe Alzheimer’s disease (an MMSE score of 20 or less). However, NICE does not recommend the use of memantine in people with moderately severe to severe Alzheimer’s (an MMSE score of 14 or less).

You may be prescribed memantine as part of a clinical trial (a type of medical research that tests one type of treatment against another). If you are currently taking memantine, you may continue to take it until you, your carers and your specialist consider it appropriate to stop.

Memantine works by blocking chemicals that are often released in large amounts in people with Alzheimer’s disease. These chemicals can damage nerve cells and prevent messages moving to and from the brain.

Side effects

Donepezil, galantamine and rivastigmine (acetylcholinesterase inhibitors) can cause side effects including:

  • nausea (feeling sick)
  • vomiting
  • diarrhoea
  • headache
  • fatigue (extreme tiredness)
  • insomnia (difficulty getting to sleep or staying asleep)
  • muscle cramps (when your muscles suddenly shorten and cause pain)

For more information about the possible side effects of a particular medication, refer to the patient information leaflet that comes with your medication.


Alzheimer’s disease is the most common form of dementia. Dementia is a syndrome (a group of symptoms) that is associated with an ongoing decline in mental abilities. The treatment for Alzheimer’s disease will follow the same pattern as treatment for dementia.

If you have been diagnosed with any other conditions as well as Alzheimer’s disease, for example, depression or incontinence (when you unintentionally pass urine or stools), these may be treated separately.

Care assessment

If you have been diagnosed with Alzheimer’s disease, your future health and social care needs will be assessed and a care plan will be drawn up. This will be coordinated by:

  • healthcare professionals, such as your GP or psychiatrist
  • social care services, which is normally your local council working in conjunction with the NHS

As part of your care assessment your functional capacity will be assessed. This involves identifying areas where you may need some assistance with your day-to-day activities. For example, areas that may be assessed include:

  • whether you can drive safely
  • whether you can wash, dress and feed yourself
  • whether you have a support network, such as family and friends
  • whether you need any financial assistance

Following the care assessment, a care plan can be drawn up to arrange support for any areas where you may need to have some help. The kind of care that you will receive may depend on what is available from your local primary care trust (PCT).


The healthcare professionals who are treating you will aim to keep you living as independently as possible. Support can be provided in many different ways. For example:

  • Grab bars and handrails can be added around your home, for example, to help you to get in and out of the bath.
  • An occupational therapist can identify problem areas in your everyday life, such as dressing yourself, and help you to work out practical solutions.
  • Cognitive stimulation programmes can be arranged. These involve taking part in activities and exercises to improve your memory, problem-solving skills and language ability.

Preventing Alzheimer’s disease

As the cause of Alzheimer’s disease is still unknown, there is no way to prevent the condition. However, there are some steps that you can take to try to delay the onset of dementia. You should:

  • stop smoking
  • avoid drinking large amounts of alcohol
  • eat a healthy, balanced diet, including at least five portions of fruit and vegetables every day
  • exercise for at least 30 minutes every day as this will improve both your physical and mental health
  • stay mentally active, for example, by reading, writing or taking an adult education course

Future research

Research into Alzheimer’s disease is continuing, and as more is revealed about the condition, other ways to treat or prevent it may be found. However, research does not always produce successful results.

The National Institute for Health and Clinical Excellence (NICE) has recommended that the following should not be used to try to prevent dementia:

  • statins (cholesterol-lowering medicines)
  • hormone replacement therapy (when powerful chemicals are taken to replace those that your body no longer produces)
  • vitamin E (found in a variety of foods, such as olive oil, nuts and seeds)
  • non-steroidal anti-inflammatory drugs (NSAIDs)