What is Alzheimer’s disease? Symptoms, causes and treatment

Alzheimer’s disease is the most common form of dementia. It is thought to be caused by a build-up of proteins in the brain which affect how the brain cells transmit messages. As time passes, more brain cells are damaged, leading to worsening symptoms.

This page, written by our dementia specialist Admiral Nurses, explores the symptoms, causes and possible treatment of Alzheimer’s disease.

What is Alzheimer’s disease?

Alzheimer’s disease is a type of dementia that mostly affects older adults, but it can also develop in younger people under the age of 65, when it is known as ‘young onset Alzheimer’s disease’. It causes problems with memory, thinking and behaviour. As a progressive condition, it will affect more and more aspects of a person’s life over time.

How does Alzheimer’s disease differ from other types of dementia?

There are many different forms of dementia, all of which are progressive conditions that cause damage to the brain.

Unlike other types of dementia, Alzheimer’s disease is thought to be caused by the abnormal build-up of two proteins in the brain, ‘amyloid’ and ‘tau’. These form structures called ‘plaques’ and ‘tangles’, which damage the brain cells. Alzheimer’s disease also reduces the levels of chemical messengers in the brain (‘neurotransmitters’) which makes it harder for messages to pass between brain cells.

As Alzheimer’s disease progresses, brain cells continue to die and parts of the brain shrink, and the levels of neurotransmitters decrease further.

Different forms of dementia have different symptoms, but in Alzheimer’s disease, the most common early sign is difficulty with memory.

How common is Alzheimer’s disease?

Alzheimer’s disease is the most common form of dementia, affecting one in 14 people over the age of 65, and one in six people over the age of 80.

It can also affect younger people and is the most common form of young onset dementia (where symptoms develop before the age of 65).

Common signs and symptoms of Alzheimer’s disease

It can be helpful to think of dementia progressing in three stages – early, middle and late stages.

Early signs of Alzheimer’s disease

The most noticeable early sign of Alzheimer’s disease is usually difficulty with memory, especially short-term memory. The person might:

• forget recent events or conversations (but they might have clear memories of the past)
• misplace items or put them in the wrong place (eg putting their keys in the fridge)
• forget appointments
• forget the names of people, objects or places
• struggle to find the right words
• repeat themselves

Other early symptoms may include:

• mood and personality changes
• feeling unsettled by unfamiliar situations or changes in routine
• becoming withdrawn
• difficulty making decisions

In the early stages of Alzheimer’s disease, the symptoms may be mild, but they can still be extremely frustrating for the person and those around them, especially if they do not understand why the changes are happening.

Symptoms of middle stage Alzheimer’s disease

In the middle stages, symptoms may include:

• increasing confusion and disorientation, eg getting lost in familiar places
• delusions (believing things that are not true, eg that a family member is trying to steal money from them)
• hallucinations (seeing or hearing things that are not there, eg a stranger in their home)
• obsessive or repetitive behaviours
• problems with speech and language
• disturbed sleep
• difficulty with spatial awareness, eg judging speed and distances

Symptoms of late stage Alzheimer’s disease

In the late stages of Alzheimer’s disease, new symptoms may develop, including:

• distressed, frustrated or angry behaviour as the person struggles to express themselves
• incontinence
• difficulty eating and swallowing
• loss of speech
• mobility problems
• weight loss
• becoming increasingly weak and frail
• frequent infections
• bouts of delirium

How quickly does Alzheimer’s disease progress?

Alzheimer’s progresses gradually; however, each person’s experience is different and it is impossible to predict how quickly they will deteriorate.

Getting an accurate diagnosis of Alzheimer’s disease as early as possible is important, as treatments to help slow its progress tend to be most effective in the early stages. A timely diagnosis also means support can be put in place to help maintain the person’s quality of life.

There is currently no cure to stop or reverse the disease.

Causes and risk factors

There are a number of causes and risk factors for Alzheimer’s disease. Some are unavoidable, but others could be reduced through lifestyle changes. Some of the causes include:

Age

Age is the biggest risk factor for developing Alzheimer’s disease. The older someone is, the more likely it becomes, but it can also occur in younger people under the age of 65.

Underlying health conditions

Some health problems can raise the risk of getting Alzheimer’s disease. These include heart and blood vessel issues such as high blood pressure and diabetes as well as obesity. People with learning disabilities, particularly Down’s syndrome, are also more likely to develop Alzheimer’s disease.

Family history

In rare cases, Alzheimer’s disease is caused by a genetic fault that runs in families, but this accounts for fewer than 1% of all people diagnosed with the condition. Alzheimer’s disease is more likely to be inherited in people whose parents developed the condition at a very young age.

Read more about genetic forms of dementia.

Sex and ethnic background

Women are slightly more likely to develop Alzheimer’s disease than men, and there is some evidence that people from African-Caribbean and South Asian backgrounds may be more at risk.

Lifestyle

Although age is the biggest factor for Alzheimer’s disease, studies suggest that the way we live can also influence our chances of developing this and other forms of dementia. Here, we list some of the lifestyle factors that could increase the risk.

Diet

A diet high in processed foods, sugar and unhealthy fats may increase the risk of Alzheimer’s disease because it can lead to conditions that affect the heart and circulatory system (cardiovascular conditions) and reduce blood flow to the brain.

The risk of developing these conditions and others than are linked to dementia can be reduced by eating a healthy, balanced diet. The NHS Eatwell Guide can help you understand which foods to eat to improve and maintain your physical and mental health.

There is also a link between alcohol and developing dementia so it’s important to keep drinking within the recommended limits.

Exercise

A lack of regular exercise can contribute to the risk of developing Alzheimer’s disease, as well as other forms of dementia. Exercise improves heart health and helps blood flow and oxygen delivery to the brain, which supports cognitive function.

Smoking

Smoking increases a person’s risk of developing dementia by damaging blood vessels and reducing blood flow to the brain. This can increase the risk of Alzheimer’s disease. Some studies show that smoking increases the risk of developing dementia by 30-50% but quitting smoking, even later in life, can reduce the risk of cognitive decline and improve overall brain health.

Sleep

It’s thought that a lack of sleep, or poor quality sleep, can lead to a build-up of proteins in the brain, which may increase the risk of Alzheimer’s disease. How much each person needs will vary, but six to eight hours’ uninterrupted sleep is ideal for most people.  The NHS has information on improving sleep.

Reducing your risk of Alzheimer’s disease

Although there is no guaranteed way to prevent Alzheimer’s disease, certain steps may help reduce the risk:

• stopping smoking
• keeping alcohol consumption within recommended limits
• eating a healthy, balanced diet with at least five portions of fruit and vegetables a day
• aiming to exercise at least five days a week for 30 minutes or more at a time
• ensuring you take any medication prescribed for diabetes, heart conditions, depression and other physical/mental health problems
• asking your GP for regular health checks, including blood pressure checks and blood tests
• having your hearing and eyesight checked regularly
• staying mentally and socially active, for example, by taking part in group activities, volunteering, reading or learning a new skill like a language or photography

Diagnosing Alzheimer’s disease

It may take several appointments and tests over a number of months to get a diagnosis of Alzheimer’s disease. This is particularly true for younger people, who typically face a much longer wait to get a diagnosis than older people.

If dementia is diagnosed early, there may be more treatment options, and support can be put in place sooner.

Medical tests

The first port of call if you are worried about symptoms of Alzheimer’s disease in yourself or someone else is the GP. They will rule out any underlying physical or mental health issues that may be contributing to the symptoms, many of which can be treated. These include depression, anxiety, vitamin deficiency, diabetes, hormonal conditions or menopause. They will ask the person:

• what their symptoms are
• when they started
• how they affect their daily life
• their family history
• their medical history

It is a good idea to keep a record of symptoms, triggers and how they affect the person to show the GP. The GP should carry out some simple physical tests, such as a blood pressure check, and refer the person for blood tests. They may request an ECG (a check of heart rhythm) and a brain scan.

Cognitive assessments

A short memory and concentration test (often known as the ‘mini mental state examination’) should be carried out by a GP as part of the assessment. This may include:

• stating the day, date and year
• naming pictures of some common objects, eg keys, kettle
• remembering and repeating a list of items
• completing a simple drawing, eg putting numbers on a clock face

If the tests rule out other conditions that may be causing the person’s symptoms, the GP should refer them to a specialist memory clinic for more detailed assessments. These may be carried out by a nurse, psychiatrist, neurologist or elderly care specialist.

Brain imaging

The person may also have further scans such as an MRI or CT scan – these produce detailed images of the brain and may show changes associated with Alzheimer’s disease or other conditions.

Preparing to speak to the doctor

It is a good idea to prepare for the appointment to ensure you get the most out of your time with the healthcare professional.

• If there is a particular GP you would like to see you can request this, although it may mean waiting longer for an appointment.
• Write down the most important things you want to discuss. If there are more than two or three things, you may wish to book a double appointment
• Keep a record of any changes in symptoms or behaviour
• Make a list of any medications being taken, including prescribed medications, over-the-counter medications, vitamin supplements and natural remedies
• If you are seeing the GP about your own symptoms, ask someone to accompany you – this may make you feel more comfortable, and they can share their own thoughts about the situation
• If you need a chaperone or interpreter, inform the surgery in advance
• If someone close to you is seeing the GP about their symptoms, it is a good idea to go with them so you can discuss anything you have noticed and offer support

Find out how to best prepare for a GP appointment.

Treatment for Alzheimer’s disease

There is currently no cure for Alzheimer’s disease. However, for some people, medication can improve the symptoms and slow its progression.

Medication

The main medications for Alzheimer’s disease are donepezil, rivastigmine and galantamine. These work by increasing the levels of a chemical called acetylcholine in the brain, which helps the brain cells communicate with each other. They are only effective in the early to middle stages of Alzheimer’s disease, and they depend on the person being physically fit and well, and able to remember to take the medication at the same time each day.

Another medication, called memantine, may be prescribed for moderate to severe Alzheimer’s disease, or if the person cannot tolerate the other treatments.

Cognitive therapy

Cognitive stimulation therapy (CST)

CST is a type of therapy that involves taking part in activities to improve memory, language skills and problem-solving abilities. It often takes place in a group, which can also provide opportunities to socialise and share experiences, but may be offered one-to-one. The memory clinic will be able to tell you if this is available in your area.

Cognitive rehabilitation

This involves working with a specialist – usually an occupational therapist – along with a family member or friend to find ways to manage particular tasks, such as using a mobile phone or cooking a meal. The aim is to get the parts of the brain that still work well to help the parts that do not. It can also be personally satisfying to accomplish a task that the person finds difficult.

Reminiscence and life story work

Many people with Alzheimer’s disease have difficulty with short-term memory, but longer-term memories may remain intact for some time. Reminiscence and life story work focus on skills, achievements and happy memories, and can improve mood and wellbeing.

Reminiscence work involves the person talking to a family member, friend or professional about their past, often using prompts such as photos, music or favourite possessions.

Life story work involves compiling a record of the person’s life, for example:

• personal details
• important relationships with family and friends
• their childhood history
• past and present employment
• important people and places
• key events from their past
• likes and dislikes
• spiritual/cultural beliefs

Life expectancy for people with Alzheimer’s disease

On average, people with Alzheimer’s disease live four to eight years after diagnosis, but some can live as long as 20 years or more. The life expectancy for people with Alzheimer’s disease varies widely depending on many factors, including age and the stage of the disease at diagnosis, other medical conditions and overall health.

It is impossible to predict the exact length of time someone may have; instead, focus on maintaining quality of life/enjoying time together rather than speculating how long they may have left.

How does Alzheimer’s disease cause you to die?

As Alzheimer’s progresses, damage to the brain affects critical functions such as breathing, mobility and swallowing. This can lead to complications like falls, infections such as pneumonia, and malnutrition. Many people with Alzheimer’s disease become increasingly frail and are unable to recover from these complications.

Living with Alzheimer’s disease

Living with Alzheimer’s disease can be difficult for the person with the diagnosis and those around them, especially as the symptoms progress. These tips may make living with the condition easier:

• Find out about local dementia services like support groups, day centres and memory cafés
• Try to keep to a daily routine to provide familiarity and stability
• Stay socially connected by continuing current activities or trying new ones
• Carry a form of identity with details of the diagnosis in case of getting lost or needing assistance outside the home – this could be sewn into a coat or bag
• A sunflower lanyard from the Hidden Disabilities store or a similar badge/ID card can be helpful to alert members of the public that the person may need support

Supporting someone with Alzheimer’s disease

While the symptoms of Alzheimer’s disease always worsen over time, a good routine and support network can help the person with the diagnosis maintain their independence and quality of life for as long as possible.

• Complete a Herbert Protocol form: a record of important information about the person that can help the police locate them if they go missing
• Look into assistive products that make daily living easier, such as medication organisers, dementia clocks and personal fall alarms
• Take a tour around the person’s home to identify possible hazards – find out how to make the home safe and comfortable
• Request a needs assessment (for the person with dementia) and a carer’s assessment (for their carer) to establish what equipment and support is available
• Encourage the person to carry on with their daily activities as far as possible to help them maintain their skills
• Be realistic about your ability to care for the person – in the middle to late stages of Alzheimer’s disease, it may be necessary to use paid carers or consider a move into a care home

Common misconceptions

Some common misconceptions about getting a diagnosis of Alzheimer’s disease are:

• You have to stop driving immediately
• You have to give up work
• You will immediately lose the ability to make decisions (loss of capacity)
• Someone else will have to manage your finances
• Alzheimer’s disease only affects older people
• Everyone with Alzheimer’s disease will have to move into a care home

While these things are likely to happen as dementia progresses, people in the early stages of Alzheimer’s disease may be able to continue with many of their usual activities with minimal changes.