What is Dementia and Alzheimer’s

Dementia is the name for a range of conditions that cause damage to the brain. This damage can affect memory, thinking, language and the ability to carry out everyday tasks. There are many conditions which cause dementia. Alzheimer’s is the most common cause. Vascular dementia, dementia with Lewy bodies and Frontotemporal dementia are other causes.

Sometimes a person may experience a mix of two types of dementia and this is called mixed dementia. Some people may be diagnosed with dementia and it may not be possible to confirm if it is Alzheimer’s or another cause of dementia.

Types of Dementia

There are many diseases that may cause dementia. The most common causes include Alzheimer’s disease, vascular dementia, dementia with Lewy bodies and Frontotemporal dementia.

What is the difference between Dementia and Alzheimer’s disease? Via by Trinity College

Alzheimer’s disease

Alzheimer’s disease is the most common and well-known cause of dementia. It is thought to cause over half of all cases. It is recognised by the build-up of protein in the brain which forms plaques and tangles that stop the brain working as it should.

Short term memory loss is often one of the first symptoms of this disease; however there are a range of early signs and symptoms including

  • Getting stuck for words;
  • Misplacing things regularly;
  • Losing track of time;
  • Changes in mood and behaviour and;
  • Difficulty in finding the way, even in familiar places.

It is important to remember that symptoms vary from person to person as everyone’s experience with the disease is unique.

One of the first things I noticed, apart from her memory, was her ability to coordinate daily tasks was deteriorating. When she cooked a meal, she might cook the vegetables first and it could be hours afterwards that she would put the meat on.

Anonymous, Galway

Vascular dementia

Vascular dementia is the second most common type of dementia and it occurs when the blood supply to the brain is damaged. There are two main types of vascular dementia; one caused by stroke (Multi-infarct dementia) and the other by small vessel disease (Subcortical dementia).

Multi-infarct dementia is a type of vascular dementia that is caused by small strokes. The strokes can be so tiny that no-one notices them happening, but the person may get worse quite suddenly and then not change again until the next stroke happens. As a result, the progression of this dementia is often described as happening in steps rather than steady gradual changes, such as in Alzheimer’s disease.

Subcortical dementia is another type of vascular dementia and is caused by very small blood vessels that are in the inner parts of the brain.

People with vascular dementia can often experience the following symptoms:

  • Difficulty concentrating and communicating
  • Memory problems
  • Depression

Dementia with Lewy bodies

Dementia with Lewy bodies is a type of dementia that shares characteristics with both Alzheimer’s disease and Parkinson’s disease. Like Alzheimer’s disease symptoms progress gradually over several years. The person will experience many of the signs and symptoms of Alzheimer’s disease and may also experience:

  • Muscle stiffness
  • Trembling of the limbs
  • A tendency to shuffle when walking
  • hallucinations (seeing things that are not there)
  • fall asleep during the day and then not sleep at night

Frontotemporal dementia

Frontotemporal dementia, including Picks Disease is a rare type of dementia which is caused by damage to different areas of the frontal and temporal lobes of the brain. During the early stages, a person’s memory may be fine but their personality, behaviour and language skills can change.

This dementia often may cause a person to:

  • Say and do things at the wrong time and in the wrong place
  • Loss of sympathy or empathy
  • Loss of interest in things or people
  • Repetitive, compulsive behaviours
  • Changes in language such as errors in grammar, slow, hesitant speech or difficulty finding the right word

The progression of this dementia is unpredictable and in the later stages symptoms are similar to those of Alzheimer’s disease.

Other forms of dementia

Other forms of dementia include Creutzfeld-Jacob Dementia and alcohol-related dementia such as Korsakoff’s syndrome. Some people with Down’s syndrome also develop dementia in middle age.

If you or your loved one are experiencing changes in your memory, mood or ability to manage, don’t worry alone. Take the next step and do something about it.

Below you will find information about early signs and symptoms, when you should visit your doctor, how a diagnosis is made and what treatment is available. You will also find tips on coping with memory loss.

Signs and Symptoms

Often the early signs of dementia may be difficult to detect. Some people experience changes in their short term memory early on, for others changes to mood or to language may be the early signs. Each person’s experience with dementia is unique and will vary between the different types of dementia

Early signs and symptoms may include:

  • Memory loss, particularly for recent events
  • Problems with language, difficulty finding the right word
  • Changes in personality, mood or behaviour
  • Becoming confused in familiar surroundings or situations
  • Difficulty in following conversations, TV programmes or reading
  • Difficulty managing money and everyday tasks
  • Difficulty solving problems or doing puzzles
  • Loss of interest in hobbies and pastimes, lack of initiative to start something or go somewhere.
  • Repeating a question or story several times without realising
  • Misplacing things by putting them in the wrong place

Most people will experience a number of these signs, and they will find they are having increased difficulty over time. In general, signs and symptoms emerge gradually. This can be difficult for both the person who is experiencing changes and for their family and friends.


There is no one test used to diagnose a type of dementia. Rather, the diagnosis involves a range of assessments and tests and this can mean that confirming a diagnosis can take time, particularly in the early stages.

A diagnosis of dementia usually begins with a General Practitioner, GP.  It can be helpful to make a note of the changes causing concern before your visit to help you to talk to the GP about them. Perhaps keep a diary to help you to do this.

The GP will generally begin an assessment by ruling out other possible causes of symptoms you are experiencing; this may involve running some tests including blood tests and memory tests as well as an overview of your general health. Some other possible causes of the symptoms you are experiencing include thyroid disorders, vitamin deficiency and side effects of some medication.

The GP may refer to a consultant who will conduct a full assessment to try to establish the cause of the symptoms.   Click here to find out who’s who in dementia care, as they can work with you to help you understand the diagnosis.

If you are under 65, you will be referred to a neurologist or a memory clinic. If you feel a referral to a specialist would be helpful you can discuss this with the GP.

The consultant will conduct a full assessment to try to establish the cause of the symptoms. They usually work with a specialist team and you may see a number of people from this team. This process usually includes

  • Blood tests,
  • A full history of family medical background,
  • A physical examination,
  • An assessment of memory, thinking and activities of daily living,
  • A brain scan (CT, MRI) to identify any changes taking place in the brain which may form part of the assessment, but this may not be required for every case.

The doctors will work directly with the person who is experiencing changes. The doctor may also ask family members to talk about any changes they see or any concerns they may have.

After the assessment, the consultant will draw together all the results and determine what is happening. It may be that the assessment is repeated at a later date in order to identify further changes and confirm a diagnosis.

What if a diagnosis is made?

A diagnosis of dementia can come as a shock, no matter how much it is expected. It is hard for everyone concerned and reassurance and support are vital. The most important thing is to try to be positive and to know that you are not alone. There are people you can talk to and supports and services that can help.

Your GP will be an important person to support you to live well with dementia. You can talk to them about your dementia, about any medications and treatments you may be prescribed, about areas such as driving and about any symptoms that may emerge.

First steps - it's good to talk about dementia via The Alzheimer Society of Ireland

Stages and Prognosis

Each person’s experience with dementia is unique to them. Dementia may last many years, sometimes progressing faster, sometimes more slowly. This means that it is not possible for anyone to tell you exactly how the condition will progress and how long a person can live with dementia.

Many people find it stressful that they do not have answers to these questions and that is normal. It is important to understand as much as you can about dementia as it can help you to come to terms with the diagnosis and what may lie ahead. It can be useful to think about the way dementia progresses in stages, however it is important to remember that this is only a guide, some symptoms may appear earlier or later or not at all.

The following provides an outline of the three stages that are associated with Alzheimer’s disease. Following this, there is a note on the progression of vascular dementia, dementia with Lewy body and Frontotemporal dementia which all have specific characteristics associated with them.

The progression of Alzheimer’s disease

On average people live 8 to 10 years from the time first symptoms emerge. However, life expectancy varies considerably depending on how old a person is when symptoms begin. A person diagnosed in their 60’s will live longer than someone diagnosed in their 90’s. Life expectancy is also affected by other illnesses the person experiences.

Early Stage

In the early stages of dementia changes are slight and it is possible to continue to do lots of things. This typically means a person may:

  • Forget things easily or repeat things frequently
  • Experience problems with language, such as appearing to be stuck for words or losing track of a conversation
  • Find new situations or places confusing
  • Show poor judgement or find it hard to make decisions
  • Lose interest in other people or activities
  • Be unwilling to try new things
  • Experience low mood, may become anxious or withdrawn
  • Feel frustrated or angry

Many people in the early stages of dementia engage in activities they enjoy but at times they may find it hard and may need to rest more frequently.

Middle Stage

As dementia progresses, changes are greater and a person will need more support to help them to manage day to day living. As a person finds it harder to do things, they may lose confidence and withdraw or be upset. Others may feel frustrated and angry and be argumentative or quick to lose their temper.

During the middle stage a person may:

  • forget recent events completely
  • find conversations, television or reading difficult to follow or confusing
  • get lost easily, even in familiar places
  • find bathing and dressing difficult or confusing
  • need reminders to eat, drink and take medication
  • find meal preparation and managing money very difficult
  • believe things are real even when they are not
  • feel restless or agitated
  • confuse time and experience difficulties with sleeping

The symptoms and behaviours that can occur during this stage are difficult for both the person with dementia and their families. There are supports and services to help and strategies for coping which are listed at the bottom of this page

Late Stage

During the late stage of dementia, a person will need increasing amounts of support and will gradually become dependent on others for nursing care. A person will become increasingly frail and may walk unsteadily; they may need a wheelchair or be confined to bed. During this stage the ability to fight even simple infections is low.

Typically, a person may:

  • have difficulty recognising people, although there may be flashes of recognition
  • experience gradual loss of speech
  • have difficulty eating and sometimes swallowing
  • experience incontinence
  • appear restless and seem to be looking for someone or something

While a person with late stage dementia may have difficulty communicating, they will often respond positively to affection, a smile, and a soothing voice. Music, scent and hand massage can bring comfort and enjoyment.

The progression of vascular dementia

Vascular dementia is generally caused by a stroke or a series of small strokes. As a result this type of dementia may progress in a ‘stepped’ manner, which differs from the more gradual progression of Alzheimer’s disease. Symptoms may appear to suddenly worsen due to a stroke and then remain level for a period of time. It may be months or years until the next stroke occurs and symptoms can then worsen. Where vascular dementia is caused by a series of small strokes, then symptoms can emerge in a more gradual way.

People with vascular dementia tend to maintain their personality and emotional responsiveness until the later stages of the condition. This can mean that people are more aware of their condition and can be more prone to depression than people with Alzheimer’s disease.

In general people with vascular dementia live for around five years after symptoms begin. In many cases, the person’s death will be caused by a stroke or heart attack.

The progression of dementia with Lewy Bodies

Half or more of people with dementia with Lewy Bodies will also develop symptoms of Parkinson’s disease. These include slowness of movement, stiffness and tremor. Other symptoms include difficulty judging distances, falls and fainting. Visual hallucinations, paranoia and delusions may also emerge.

In the early stages of this dementia, the abilities of the person may fluctuate drastically, even during the course of a day. This can be very confusing for all concerned.

In the later stages, this dementia progresses in a similar way to Alzheimer’s disease. People usually live for six to twelve years following onset of symptoms.

Each person’s experience with their dementia is unique to them, and there is no way to say exactly how their dementia will progress, which symptoms will emerge and when and how long they may live with their condition. The above is just a guide to help to understand how a dementia may progress however it is important to note that everyone’s experience with dementia is unique to them.

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