We have decided to concentrate on the most common types of dementia – Alzheimer’s disease, which, like the others, is a progressive disease. This means the structure and chemistry of the brain become increasingly damaged over time. The person’s ability to remember, understand, reason and communicate will gradually decline. As the dementia worsens, the person will need more and more support with daily living. Their behaviour and mood will also change. Dementia has three stages – early, middle and late.  This can be a useful way of understanding the changes that occur over time. However, it is important to realise that this view of dementia can only provide a rough guide to the course of the illness. This is because:

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

BEFORE SYMPTOMS BEGIN: There is good evidence that, by the time most people develop any symptoms of dementia, the underlying disease has been causing damage to their brain for years. It is likely that any medication designed to slow down or prevent the diseases that cause dementia would work in this early phase, before the disease is fully established.

Over time, the changes in the brain will begin to cause mild symptoms which are initially not bad enough to count as dementia. Subtle problems in areas such as memory, reasoning, planning or judgement may cause difficulties with more demanding tasks (e.g. preparing a meal) but they will not yet significantly affect daily life. A person at this stage may be given a diagnosis of mild cognitive impairment (MCI). About 10% – 15% of people with this diagnosis will go on to develop dementia each year.

RATE OF PROGRESSION: The speed at which dementia worsens varies widely. There are some differences between the different dementias – Alzheimer’s disease, for example, seems to have the slowest progression on average – but much of the variation is from person to person.

EARLY (MILD) STAGE: Alzheimer’s disease usually begins with very minor changes in the person’s abilities or behaviour. At the time, such signs can often be mistakenly attributed to stress or bereavement or, in older people, to the normal process of ageing. It is often only when looking back that it is realised that these signs were probably the beginnings of dementia.

Loss of memory of recent events is a common early symptom. The person will have difficulty recalling things that happened recently and also with learning new information. Someone with Alzheimer’s may:

• Mislay items around the house
• Forget recent conversations or events
• Struggle to find the right word in conversation or lose the thread of what is being said
• Become slower at grasping new ideas and unwilling to try out new things
• Become confused or lose track of the day or date
• Show poor judgement, or find it harder to plan or make decisions
• Have problems judging distance or seeing objects in 3D (e.g. when navigating stairs or parking the car)
• Lose interest in other people or activities

MIDDLE (MODERATE) 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 life. 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 sentence over and over. They may also fail to recognise people or confuse them with others. At this stage, the person might put themselves or others at risk through their forgetfulness, for example by not lighting the gas on the cooker or forgetting to take medication. Other signs include:

• Becoming confused about where they are, or walking off and becoming lost
• Muddling up time and getting up at night because they are mixing up night and day
• Behaving in ways that may seem unusual, such as going outside in their nightclothes, becoming very agitated or unknowingly behaving in socially inappropriate ways
• Experiencing difficulty with perception and, in some cases, having delusions (strongly believing things that are not true) or, less often, hallucinations (usually, seeing things that are not really there). 

LATE (SEVERE) STAGE: 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, surroundings or even those closest to them, although there may be sudden flashes of recognition.

The person may also become increasingly weak. They may start to shuffle or walk unsteadily, eventually spending more time in bed or a wheelchair. Other symptoms may include:

• Difficulty 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 the person may repeat a few words or cry out from time to time