Alzheimer’s disease


Alzheimer’s disease

Alzheimer's disease is the most common type of dementia. Worldwide, 47 million people are living with dementia.

The term "dementia" describes a loss of mental ability associated with gradual death of brain cells.

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:

increasing age

a family history of the condition

previous severe head injuries

lifestyle factors and conditions associated with cardiovascular 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.

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 and disorientation

personality changes, such as becoming aggressive, demanding and suspicious of others

hallucinations (seeing things that are not there) and delusions (believing things that are untrue)

problems with language and speech

problems moving around without assistance

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 one in every six people over the age of 80.

However, around 1 in every 20 cases of Alzheimer's disease affects people between 40 and 65 years of age.

Getting a diagnosis

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

However, an early diagnosis of Alzheimer's disease gives you the best chance to prepare and plan for the future, as well as receive any treatment that may help.

If you are 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 is 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 to confirm the diagnosis and draw up a treatment plan.

How Alzheimer's disease is treated

There is no cure for Alzheimer's disease, but medication is available that can help improve some of the symptoms and slow down the development 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 so it's easier to move around.

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


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 not usually the actual cause of death, but it is often a contributing factor. For example, a leading cause of death in people with Alzheimer's disease is pneumonia (lung infection), which may go untreated because people with the condition often aren't able to recognise that they're ill, or may not be able to tell someone they are feeling unwell.

Can Alzheimer's disease be prevented?

As the exact cause of Alzheimer's disease is not clear, there is no known way to prevent the condition. However, there are some steps you can take that may help reduce your risk or delay the onset of dementia, such as:

stopping smoking if you smoke and cutting down on alcohol

eating a healthy, balanced diet

having regular health tests as you get older

staying physically fit and mentally active

Taking these steps also has other health benefits, such as lowering your risk of cardiovascular disease and improving your overall mental health.

Symptoms of Alzheimer's disease

The symptoms of Alzheimer's disease progress slowly over several years. They are often similar to those of other conditions and may initially be put down to old age.

The rate at which the symptoms progress differs for each individual and it is not possible to predict exactly how quickly it will get worse.

In some cases, infections or medications can be responsible for the worsening of symptoms. Anyone with Alzheimer's disease whose symptoms are rapidly getting worse should be seen by a doctor so these causes can be ruled out.

Stages of Alzheimer's disease

Generally, the symptoms of Alzheimer's disease are divided into three main stages.

Early symptoms

In the early stages, the main symptom of Alzheimer's disease is memory lapses. For example, someone with early Alzheimer's disease may:

forget about recent conversations or events

forget the names of places and objects

repeat themselves regularly, such as asking the same question several times

show poor judgement or find it harder to make decisions

become unwilling to try out new things or adapt to change

There may also be some early signs of mood changes, such as increasing anxiety or agitation, or periods of confusion.

Middle stage symptoms

As Alzheimer's disease develops, memory problems will get worse and someone with the condition may find it increasingly difficult to remember the names of people they know and may struggle to recognise their family and friends.

Other symptoms may also develop, such as:

increasing confusion and disorientation – for example, not knowing where they are and walking off and getting lost

obsessive, repetitive or impulsive behaviour

delusions (believing things that are untrue)

problems with speech or language (aphasia)

disturbed sleep

changes in mood, such as frequent mood swings,depression and feeling increasingly anxious, frustrated or agitated

difficulty performing spatial tasks, such as judging distances

problems with eyesight, such as poor vision or hallucinations(seeing things that are not there)

By this stage, someone with Alzheimer's disease will usually need support to help them with their everyday living. For example, they may need help eating, washing, getting dressed and using the toilet.

Later symptoms

In the later stages of Alzheimer's disease, the symptoms become increasingly severe and distressing for the person with the condition, as well as their carers, friends and family.

Hallucinations and delusions will often become worse and the person with the condition may start to become violent, demanding and suspicious of those around them.

A number of other symptoms may also develop as Alzheimer's disease progresses, such as:

difficulty eating and swallowing (dysphagia)

difficulty changing position or moving around without assistance

considerable weight loss (although some people eat too much and put on weight)

unintentional passing of urine (urinary incontinence) or stools (bowel incontinence)

gradual loss of speech

significant problems with short- 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.

Seeking medical advice

If you are 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.

Memory problems are not just caused by dementia – they can also be caused by depression, stress, medications or other health problems. Your GP will be able to carry out some simple checks to try to find out what the cause may be, and they can refer you to a specialist for further tests if necessary.

Causes of Alzheimer's disease

Alzheimer's disease is caused by parts of the brain wasting away (atrophy), which damages the structure of the brain and how it works.

It is not known exactly what causes this process to begin, although people with Alzheimer's disease have been found to have abnormal amounts of protein (amyloid plaques), fibres (tau tangles) and a chemical called acetylcholine in the brain.

These reduce the effectiveness of healthy neurons (nerve cells that carry messages to and from the brain), gradually destroying them.

Over time, this damage spreads to several areas of the brain, such as the grey matter (responsible for processing thoughts) and the hippocampus (responsible for memory).

Increased risk

Although it is still unknown what triggers Alzheimer's disease, several factors are known to increase your risk of developing the condition.


Age is the single most significant 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. Around 1 in 20 people with the condition are under 65. This is called early-onset Alzheimer's disease and it can affect people from around 40 years of age.

Family history

The genes you inherit from your parents can contribute to your risk of developing Alzheimer's disease, although the actual increase in risk is small if you have a close family member with the condition.

However, in a few families, Alzheimer's disease is caused by the inheritance of a single gene, and the risks of the condition being passed on are much higher.

If several of your family members have developed dementia over the generations, it may be appropriate to seek genetic counselling for information and advice about your chances of developing Alzheimer's disease when you are older.

The Alzheimer's Society website has more information about genetics and dementia.

Down's syndrome

People with Down's syndrome are at a higher risk of developing Alzheimer's disease.

This is because the genetic fault that causes Down's syndrome can also cause amyloid plaques to build up in the brain over time, which can lead to Alzheimer's disease in some people.

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) have been found to be at higher risk of developing Alzheimer's disease.

Cardiovascular disease

Research shows that several lifestyle factors and conditions associated with cardiovascular disease can increase the risk of Alzheimer's disease.

These include:




high blood pressure

high cholesterol

You can help reduce your risk by stopping smoking if you smoke,eating a healthy, balanced diet, and having regular health checks as you get older. It is also important to keep as active as possible, both mentally and physically, to help reduce the risk of Alzheimer's disease.

Diagnosing Alzheimer's disease

See your GP if you are worried about your memory or think you may have dementia.

If you're worried about someone else, you should encourage them to make an appointment and perhaps suggest that you go along with them.

An early diagnosis gives you the best chance to prepare and plan for the future, as well as receive any treatment that may help.

Seeing your GP

Memory problems are not just caused by dementia – they can also be caused by depression, stress, medications or other health problems. Read about common causes of memory loss.

Your GP will be able to carry out some simple checks to try to find out what the cause may be. They can refer you to a specialist for further tests if necessary.

Your GP will ask about your symptoms and other aspects of your health, and will carry out a physical examination. They may also organise some blood tests and ask about any medication you are taking to rule out other possible causes of your symptoms.

You may also be asked some questions or be asked to carry out some simple activities to assess any problems with your memory or your ability to think clearly. This can help your GP decide if you need to be referred to a specialist for further assessment.

Referral to a specialist

Your GP may refer you to a specialist to help with your 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)

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 is no simple and reliable test for diagnosing Alzheimer's disease, but your specialist can help assess your memory and thinking skills, and arrange further tests to rule out other conditions.

Assessing your mental abilities

A specialist will usually assess your mental abilities using a special questionnaire. 

One widely used test is the mini mental state examination (MMSE). This involves being asked to carry out activities such as memorising a short list of objects correctly and identifying the current day of the week, month and year.

The MMSE is not used to diagnose Alzheimer's disease, but it is useful for assessing the level of mental impairment that a person with the condition may have. This helps specialists make decisions about treatment and whether further tests are necessary.


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:

computerised 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

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

After diagnosis

It may take several appointments and tests over months, or even years, before a diagnosis of Alzheimer's disease can be confirmed.

For some people, a diagnosis of Alzheimer's disease is a huge shock, whereas for others it simply confirms what had been suspected for a long time.

If you've just had a diagnosis of dementia, you're probably feeling numb, scared and unable to take everything in, so give yourself a little time to adjust. It might help to talk things through with family and friends.

Once the initial feelings have passed, it's important to think about moving forward and creating an action plan for the future. Dementia is a progressive illness, so the sooner you take care of legal, financial and healthcare matters, the better.

Treating Alzheimer's disease

There is currently no cure for Alzheimer's disease, although medication is available that can temporarily reduce some symptoms or slow down the progression of the condition in some people. Support is also available to help someone with the condition cope with everyday life.

Care plan

Once you've been diagnosed with Alzheimer's disease, your future health and social care needs will need to be assessed and a care plan drawn up. 

A care plan is a way of ensuring you receive the right treatment for your needs. It involves identifying areas where you may need some assistance, such as:

what support you or your carer need for you to remain as independent as possible

whether there are any changes that need to be made to your home to make it easier to live in

whether you need any financial assistance

Healthcare professionals (such as your GP or psychiatrist) and social care services, which is normally your local council working in conjunction with the will usually both be involved in helping draw up and implement care plans.


A number of medications may be prescribed for Alzheimer's disease to help temporarily improve some symptoms and slow down the progression of the condition.

These include donepezil, galantamine, rivastigmine and memantine. Whether these medications are used will depend on the severity of the condition.

Donepezil, galantamine and rivastigmine (known as AChE inhibitors) can be prescribed for people with early to mid-stage Alzheimer's disease. Memantine may be prescribed for people with mid-stage disease who cannot take AChE inhibitors, or for those with late-stage disease.

There is no difference in the effectiveness of the three different AChE inhibitors, although some people respond better to certain types or have fewer side effects.

All of these medications should only be prescribed by specialists such as psychiatrists, neurologists and physicians specialising in the care of older people.

If you are caring for someone with Alzheimer's disease, your views should be taken into account when prescribing medication as well as at regular assessments. These assessments take place to ensure the medication is having a worthwhile effect. 

Side effects

Donepezil, galantamine and rivastigmine can cause side effects such as:

feeling and being sick



fatigue (extreme tiredness)

insomnia (difficulty getting to sleep or staying asleep)

muscle cramps

Common side effects of memantine include dizziness, headaches, tiredness, constipation, problems with balance, and shortness of breath.

For more information about the possible side effects of your specific medication, refer to the patient information leaflet that comes with it or look up your medication in the Alzheimer's disease medicines guide.

Supportive measures and treatments

In addition to medication, treatment for Alzheimer's disease involves a wide range of other measures and treatments to help people with dementia live as independently as possible.

For example:

an occupational therapist can identify problem areas in your everyday life, such as dressing yourself, and help you work out practical solutions

grab bars and handrails can be added around your home – for example, to help you get in and out of the bath

psychological treatments, such as cognitive stimulation, may be offered to help improve your memory, problem-solving skills and language ability

Medication, other psychological therapies, such as cognitive behavioural therapy, and relaxation therapies may also be offered to help reduce any depression, anxiety, agitation, hallucinations, delusions and challenging behaviour that often feature with Alzheimer's disease.

Practical tips for people with Alzheimer's

If you have Alzheimer's disease, you may find it useful to:

keep a diary and write down things that you want to remember

pin a weekly timetable to the wall

put your keys in an obvious place, such as in a large bowl in your living room

have a daily newspaper delivered to remind you of the day and date

put labels on cupboards and drawers

keep useful telephone numbers by the phone

write yourself reminders – for example, put a note on the front door to remind you to take your keys with you if you go out

programme people's names and numbers into your telephone

set the alarm on your watch to act as a reminder

install safety devices such as gas detectors and smoke alarms throughout your home

It may also be helpful to get in touch with a local or national Alzheimer's or dementia support group such as the Alzheimer's Societyfor more information and advice about living with Alzheimer's disease.

Palliative care

People with dementia often live for many years after their diagnosis. However, as it is a progressive condition, it's wise to make plans well in advance of the end-of-life phase.

End-of-life care, or palliative care, provides support for people with an incurable illness so they are able to live as well as possible until their death. It also involves support for family members. Care can be provided at home, a hospice, a care home or hospital.

For people nearing the end of life, their care team should assess their needs, make them feel comfortable and enable them to die with dignity in a place of their choosing.

Preventing Alzheimer's disease

As the exact cause of Alzheimer's disease is still unknown, there is no way to prevent the condition. However, there are some steps you can take that may help to delay the onset of dementia.

Reducing your risk of cardiovascular disease

Cardiovascular disease (disease of the heart or blood vessels) has been linked with an increased risk of Alzheimer's disease and vascular dementia.

You may be able to reduce your risk of developing these conditions – as well as other serious problems, such as strokes and heart attacks – by taking steps to improve your cardiovascular health, including: 

stopping smoking if you smoke

avoiding drinking large amounts of alcohol

eating a healthy balanced diet, including at least five portions of fruit and vegetables every day

exercising for at least 150 minutes (2 hours and 30 minutes) every week by doing moderate-intensity aerobic activity (such as cycling or fast walking) – this will improve both your physical and mental health

make sure your blood pressure is checked and controlled through regular health tests

if you have diabetes, make sure you keep to the diet and take your medication

Staying mentally active

There is some evidence to suggest that rates of dementia are lower in people who remain as mentally, physically and socially active as possible throughout their lives, as well as among those who enjoy a wide range of different activities and hobbies.

It may possible to reduce your risk of Alzheimer's disease and other types of dementia by:


writing for pleasure

learning foreign languages

playing musical instruments

taking part in adult education courses

playing tennis

playing golf


group sports, such as bowling


However, there is currently no clear evidence that suggests playing "brain training" computer games reduces the risk of dementia.

Future research

Research into Alzheimer's disease is continuing. As more is revealed about the condition, other ways to treat or prevent it may be found.

The National Institute for Health and Care Excellence (NICE) has advised that there is not currently evidence to support the use of the following 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)