In plain English
Dementia produces a varied and changing pattern of symptoms across cognition, mood, sleep, behaviour and physical health. This section explains each of the most common symptom groups in plain English, what is typical at each stage, and when to seek further help.
How to use this section
Dementia is not a single experience. The symptoms vary by subtype, by stage, and by the person's individual history and personality. This section is organised by symptom rather than diagnosis. Whether you are reading because you have just been diagnosed, because a family member is showing changes, or because you are a clinician looking for a quick refresher, you should be able to find a clear explanation here.
Use the links below to move to the symptom that most concerns you. Each page covers what the symptom looks like, what causes it, what helps, and when to escalate.
Cognitive symptoms
- Memory loss: short-term recall, learning new information, repetition, misplacement, and the difference between normal age-related forgetting and dementia.
- Word finding and language: anomia, halting speech, simplification of vocabulary, and pointers to Primary Progressive Aphasia.
- Disorientation: confusion about time, place and person, and how this differs from Delirium.
- Visuospatial difficulties: judging distance, navigating, recognising objects from unusual angles, the clock-drawing test.
Mood and behaviour
- Mood, anxiety and depression: depression as a mimic of dementia, depression as a complication of dementia, and how to tell the difference.
- Apathy and withdrawal: loss of interest and motivation, and why this is rarely "just laziness".
- Agitation and aggression: the most distressing of the Behavioural and Psychological Symptoms of Dementia, what triggers them, and how to respond.
- Wandering and getting lost: the safety implications, and the role of GPS trackers and locator devices.
- Hallucinations and delusional thinking: visual and auditory hallucinations, paranoia and delusional misidentification, and how Dementia with Lewy Bodies differs.
- Sundowning: the late-afternoon restlessness and confusion familiar to many carers.
Sleep
- Sleep disturbance and REM Sleep Behaviour Disorder: insomnia, day-night reversal, dream enactment, and where this points to specific dementia subtypes.
Physical symptoms
- Falls and mobility: gait changes, balance, falls prevention.
- Continence: urinary and bowel changes, what helps.
- Swallowing, weight loss and nutrition: dysphagia, appetite change, when to ask for a SALT review.
Acute deterioration
- Acute confusion (Delirium superimposed on dementia): a sudden change in alertness, attention or behaviour usually has a medical cause that needs prompt review.
How symptoms change over time
The symptoms above will change in nature and severity over the course of dementia. Three broad stages help to set expectations:
- Mild dementia. Memory and word-finding difficulty are usually most prominent. Daily independence is preserved.
- Moderate dementia. Behavioural and psychological symptoms tend to emerge. Help is needed with several day-to-day activities.
- Severe dementia. Communication is more limited, behavioural symptoms may settle as activity reduces, and physical symptoms (mobility, swallowing, continence) become prominent.
The trajectory varies between subtypes and between individuals. A symptom that is troubling at one stage may settle as the disease progresses.
When to seek help
Three patterns should prompt a call to your GP:
- Sudden change in alertness, attention or behaviour, which often signals Delirium from a treatable cause (infection, constipation, medication change, dehydration).
- New psychotic symptoms or aggression, particularly if they put the person or others at risk.
- New physical symptoms: a fall, swallowing concerns, significant weight loss, marked deterioration in mobility.
For non-urgent concerns, your memory clinic or GP can review the management plan and consider whether additional input (occupational therapy, speech and language therapy, psychology, social care) would help.
Where The Dementia Service fits in
If you would value a structured review of the symptom picture and a clear ICD-11 aligned plan, The Dementia Service can assess and write to your GP within a few weeks.
Frequently asked questions
What is usually the first symptom of dementia?
In Alzheimer's Disease, the most common first symptom is short-term memory loss, often noticed by family before the person themselves. In Frontotemporal Dementia, personality or language change usually comes first. In Dementia with Lewy Bodies, fluctuating attention, visual hallucinations or REM Sleep Behaviour Disorder may pre-date memory loss.
Is it normal to forget names as you get older?
Occasional name forgetting is part of normal ageing. The pattern of dementia is that memory difficulty is more frequent, more disruptive, and includes recent conversations and events, not only names.
What is BPSD?
Behavioural and Psychological Symptoms of Dementia (BPSD) is the umbrella term for agitation, aggression, psychosis, depression, anxiety, apathy and other non-cognitive symptoms. They are very common, particularly in moderate dementia.
When should I worry about a sudden change?
Sudden changes in alertness, attention or behaviour, especially over hours or days, usually indicate Delirium from a treatable cause. Contact your GP the same day.
Are physical symptoms part of dementia?
Yes. Gait change, falls, continence problems, swallowing difficulties and weight loss can all be part of dementia, particularly in moderate to severe stages, and have their own management.
References
- World Health Organization. ICD-11 Chapter 06: Neurocognitive disorders.
- NICE NG97: Dementia, assessment, management and support.
- Cerejeira J, Lagarto L, Mukaetova-Ladinska EB. Behavioral and psychological symptoms of dementia. Front Neurol 2012;3:73.
- Alzheimer's Society. Symptoms and stages of dementia.
