Alzheimer's Society

Although everyone experiences dementia in their own individual way, it can be helpful to think of the progression of dementia as a series of stages. This information sheet outlines the characteristics of early, middle and late stage Alzheimer's disease, and briefly looks at other forms of dementia.

Alzheimer's disease

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.

• Some symptoms may appear earlier or later than indicated here, or not at all.
• The stages may overlap - the person with Alzheimer's may need help with one task, but may be able to manage another activity on their own.
• Some symptoms, such as wandering, may appear at one stage and then vanish, while others such as memory loss will worsen over time.

The way we experience Alzheimer's will depend on many factors, including our physical make-up, our emotional resilience and the support we can rely on.

Early stage

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 short term memory is a common early sign. The person with Alzheimer's may forget about recent conversations or events. They may repeat themselves. They may be slower at grasping new ideas or lose the thread of what is being said. The person with Alzheimer's may sometimes be confused. They may show poor judgment or find it harder to take decisions. Other symptoms may include a loss of interest in other people or activities, a readiness to blame others for 'stealing' mislaid items and an unwillingness 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 a person with dementia is more likely to retain their sense of self-worth if they are given the chance to do things for themselves, with support if necessary. For more information see the Alzheimer's Society's advice sheet on Maintaining skills.

People with dementia may also be anxious and agitated. They may experience distress over their failure to manage tasks. They may be in need of reassurance. Try to talk to the person you are caring for, and give them as much emotional support as you can.

Middle stage

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.

The person is 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 owing to frustration, or they may become very clinging. 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, such as omitting to light the gas
• behaving in ways which may seem inappropriate, such as going outside in their nightclothes
• experiencing difficulty with perception, and in some cases hallucinations.

Late stage

At this stage, the person with Alzheimer's will need even more help, gradually becoming totally dependent on others for nursing care. Loss of memory may be almost complete, 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 will also become increasingly physically frail. They may start to shuffle or walk unsteadily, eventually becoming confined to bed or a wheelchair. Other symptoms may include:

• Diffdifficulty in eating and sometimes in swallowing
• considerable weight loss, although a few 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.

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.

Although the person with Alzheimer's may seem to have little understanding of speech and may not recognise those around them, they may still respond to affection, to people talking in a calm soothing voice, or they may enjoy scents, music or stroking a pet.

The Alzheimer's Society publishes a range of fact sheets on how to care for someone with dementia in the middle and late stages.

Vascular dementia

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. This contrasts with the gradual decline many people with Alzheimer's disease experience.

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 the Alzheimer's Society's information sheet What is vascular dementia?

Fronto-temporal lobe dementia (including Pick's disease)

This type of dementia is caused by damage to the frontal and/or temporal lobes of the brain, the areas responsible for our behaviour, our emotional responses and our language skills.

During the early stages the memory may be unaffected. However, there may be other changes. For example, the person may seem more 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 later stages the symptoms are more similar to those experienced in Alzheimer's disease.

For more information see the Alzheimer's Society's information sheet What is fronto-temporal dementia (including Pick's disease)?

Dementia with Lewy bodies

Dementia with Lewy bodies gets its name from microscopic deposits which are found in the brain after death. These cause the degeneration and the death of nerve cells in the brain.

Half or more of those affected also develop signs and symptoms of Parkinson's disease such as slowness or 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 which often puzzles carers is that the abilities of the affected person often fluctuate.

For more information see the Alzheimer's Society's information sheet What is dementia with Lewy bodies (DLB)?

Information sheet 458

Last updated: August 2007
Last reviewed: August 2007