Each person experiences dementia in their own way, but it can be helpful to think of the way it progresses as a series of stages. This factsheet outlines the characteristics of early-, middle- and late-stage Alzheimer’s disease, and briefly looks at how other forms of dementia progress.
Alzheimer’s disease is a progressive illness. This means that the structure and chemistry of the brain become increasingly damaged over time. The person’s ability to remember, understand, communicate and reason will gradually decline. Looking at Alzheimer’s disease as a series of three stages can be a useful way of understanding the changes that occur over time. But it is important to realise that this view of Alzheimer’s can only provide a rough guide to the course of the disease. This is because:
- Some symptoms may appear earlier or later than indicated here, or not at all.
- The stages may overlap – the person may need help with one task, but may be able to manage another activity on their own.
- Some symptoms, such as walking about, may appear at one stage and then vanish, while others such as memory loss will worsen over time.
The way that a person experiences Alzheimer’s disease will depend on many factors, including their physical make-up, their emotional resilience and what support they can rely on.
Alzheimer’s disease usually begins gradually with very minor changes in the person’s abilities or behaviour. At the time, such signs are often mistakenly attributed to stress or bereavement or, in older people, to the normal process of ageing. It is often only when looking back that we realise that these signs were probably the beginnings of the dementia.
Loss of memory for recent events is a common early sign. Someone with Alzheimer’s may:
- forget about recent conversations or events
- repeat themselves
- become slower at grasping new ideas, or lose the thread of what is being said
- sometimes become confused
- show poor judgement, or find it harder to make decisions
- lose interest in other people or activities
- develop a readiness to blame others for taking mislaid items
- become unwilling to try out new things or adapt to change
If you are caring for someone with Alzheimer’s disease, there’s a lot you can do in the early stages to help the person you are caring for maintain their independence. It may be tempting to do things for them, but they are more likely to retain their sense of self-worth if they are given the chance to do things for themselves, with support if necessary. (See Factsheet 521, Maintaining everyday skills.)
The person may also become anxious and agitated. They may experience distress over their failure to manage tasks, and may need some reassurance. If this is the case, try to talk to them, and give them as much emotional support as you can.
As Alzheimer’s disease progresses, the changes become more marked. The person will need more support to help them manage their day-to-day living. They may need frequent reminders or help to eat, wash, dress and use the toilet. They are likely to become increasingly forgetful – particularly of names – and may sometimes repeat the same question or phrase over and over because of the decline in their short-term memory. They may also fail to recognise people or confuse them with others.
Some people at this stage become very easily upset, angry or aggressive – perhaps because they are feeling frustrated – or they may lose their confidence and become very clingy. Other symptoms may include:
- becoming confused about where they are, or wandering off and becoming lost
- becoming muddled about time and getting up at night because they are mixing up night and day
- putting themselves or others at risk through their forgetfulness – for example, by not lighting the gas on the cooker
- behaving in ways that may seem unusual, such as going outside in their nightclothes
- experiencing difficulty with perception, and in some cases hallucinations
At this stage, the person with Alzheimer’s will need even more help, and will gradually become totally dependent on others for nursing care. Loss of memory may become very pronounced, with the person unable to recognise familiar objects or surroundings or even those closest to them, although there may be sudden flashes of recognition.
The person may also become increasingly frail. They may start to shuffle or walk unsteadily, eventually becoming confined to bed or a wheelchair. Other symptoms may include:
- difficulty in eating and, sometimes, swallowing
- considerable weight loss – although some people eat too much, and put on weight
- incontinence, losing control of their bladder and sometimes their bowels as well
- gradual loss of speech, though they may repeat a few words or cry out from time to time
The person may become restless, sometimes seeming to be searching for someone or something. They may become distressed or aggressive – especially if they feel threatened in some way. Angry outbursts may occur during close personal care, usually because the person does not understand what is happening. Those caring for the person should try not to take this personally.
Although the person may seem to have little understanding of speech, and may not recognise those around them, they may still respond to affection and to being talked to in a calm soothing voice, or they may enjoy scents, music, or stroking a pet.
For more information about this stage of Alzheimer’s disease, see Factsheet 417, Later stages of dementia. For more detailed information about Alzheimer’s disease in general, see Factsheet 401, What is Alzheimer’s disease?
In vascular dementia, which is commonly caused by a stroke or a series of small strokes, brain cells are deprived of oxygen and die. This can occur in distinct parts of the brain, leaving other areas relatively unaffected.
Some people with vascular dementia find that symptoms remain steady for a time and then suddenly decline as the result of another stroke. Others experience a more gradual decline.
It is sometimes difficult to determine whether people have Alzheimer’s or vascular dementia. It is also possible to be affected by both.
For more information, see Factsheet 402, What is vascular dementia?
Fronto-temporal Dementia (including Pick’s disease)
This type of dementia is caused by damage to the frontal and/or temporal lobes of the brain. These are the areas responsible for our behaviour, our emotional responses and our language skills.
During the early stages of fronto-temporal dementia, memory for recent events may be unaffected. However, there may be other changes. For example, the disease may cause some people to appear uncharacteristically selfish and unfeeling. They may behave rudely, or may seem more easily distracted. Other symptoms may include loss of inhibition, ritualised behaviour and a liking for sweet foods. In a small number of cases, a person’s first problems may be with recalling the names of objects and comprehending words (semantic dementia) or with producing fluent speech (progressive non-fluent aphasia).
In later stages the symptoms are more similar to those experienced in Alzheimer’s disease.
For more information, see Factsheet 404, What is fronto-temporal dementia (including Pick’s disease)?
Dementia with Lewy Bodies
Dementia with Lewy bodies gets its name from microscopic deposits that are found in the brain after death. These cause the degeneration and eventual death of nerve cells in the brain.
Half or more of those affected by dementia with Lewy bodies also develop signs and symptoms of Parkinson’s disease, such as slowness of movement, stiffness and tremor. They may also have difficulty in judging distances, and are more prone to falls. People with this type of dementia also commonly experience visual hallucinations. One feature of this type of dementia that often puzzles those around them is that the abilities of the affected person may fluctuate from day to day, or even during the course of a single day.
In the later stages, the symptoms are often very similar to those experienced in Alzheimer’s disease.
For more information, see Factsheet 403, What is dementia with Lewy bodies?
For details of Alzheimer’s Society services in your area, visit alzheimers.org.uk/localinfo
For information about a wide range of dementia-related topics, visit alzheimers.org.uk/factsheets
Last updated: March 2010
Last reviewed: August 2008
Reviewed by: Dr Sebastian Crutch, Neuropsychologist, Dementia Research Centre, Institute of Neurology, UCL, London, and Professor Robert Baldwin, Consultant Psychiatrist and Professor, University of Manchester.