Disease progression varies considerably, but broadly falls into four phases:

Early stage 

This is often misattributed to stress, bereavement or normal ageing. Signs and symptoms include mood changes; loss of short-term memory; confusion; poor judgement; unwillingness to make decisions; anxiety, agitation or distress over perceived changes, and an inability to manage everyday tasks.

Moderate stage 

At this stage, more support is needed for tasks of everyday living, including reminders to eat, wash, dress and use the lavatory. People are increasingly forgetful and may fail to recognise others. Distress, aggression and anger are common, perhaps due to frustration. Risks include wandering and getting lost, leaving taps running or the gas on, inappropriate behaviour, dressing incorrectly, loss of the day/night cycle and hallucinations. 

Late stage 

Characteristics at this stage include an inability to recognise familiar objects, surroundings or people €“ although there can be some flashes of recognition. Increasing physical frailty means they may start to shuffle or walk unsteadily, eventually becoming confined to bed or a chair. Difficulty eating and sometimes swallowing, weight loss, double incontinence and gradual loss of speech all occur in this late stage.

End of life stage 

This stage requires good palliative care services.