Dementia: a guide for families from a consultant geriatrician

Written and reviewed by Dr Pravin Jha, Consultant Geriatrician (MBBS, MD, DM, DGM, FRCP, MBA). Last reviewed: 28 September 2026.

Dementia is a progressive decline in memory and other thinking abilities that is severe enough to affect everyday life. I am a consultant geriatrician, and I wrote this guide for families: how to recognise the early signs, how diagnosis works, what treatment can and cannot do, how dementia progresses and where to find practical support.

In this guide:

Early signs and when to seek help

For a fuller account of how the early signs differ between types of dementia, see early signs of dementia and my geriatrician's guide to dementia signs, diagnosis and treatment.

What are the 10 warning signs of dementia?

The list of ten warning signs that circulates online was written by the US Alzheimer's Association. In short: memory loss that disrupts daily life; difficulty planning or solving problems; trouble with familiar tasks; confusion about time or place; difficulty judging distance or reading; problems finding words or following conversation; misplacing things and being unable to retrace steps; poor judgement, for example with money; withdrawal from usual activities; and changes in mood or personality. What matters is a change from the person's usual level that persists, not a single lapse.

What are the 10 warning signs of Alzheimer's disease?

It is the same list, because it was written with Alzheimer's disease in mind. In Alzheimer's disease the first change is usually in recent memory: repeating questions, forgetting recent conversations and relying on notes or a partner. Other types can begin differently. Vascular dementia often shows first as slowed thinking and difficulty planning, dementia with Lewy bodies as fluctuating alertness or visual hallucinations, and frontotemporal dementia as a change in behaviour or language rather than memory.

How do I know if I have cognitive issues?

Occasional lapses, such as a name on the tip of the tongue, happen at every age and become more frequent with tiredness, stress and low mood. The features that deserve assessment are a clear change from your own previous level, difficulties that are getting worse over months, problems with everyday tasks such as money, medicines or appointments, and concern from the people close to you. Online memory tests cannot diagnose or exclude a problem. A proper assessment also looks for treatable contributors: medicines, sleep, mood, hearing, and thyroid or vitamin problems.

What should I do if I suspect my husband has dementia?

Note specific examples and when they began: missed bills, repeated questions, getting lost on a familiar route, a change in personality. Raise it gently, at a calm moment, as a health check rather than a memory test; many people are frightened of the word dementia. Offer to go with him, because an account from someone who knows him well is an essential part of any assessment. If he has become confused suddenly, over hours or days, that is more likely to be delirium from an infection or a medicine and needs medical attention the same day.

Does dementia start with dizziness?

No. Dizziness is not a typical early sign of dementia. In older adults it usually comes from the inner ear, a fall in blood pressure on standing, medicines or a heart rhythm problem, and it needs assessment in its own right; I explain the causes in dizziness in older adults. The exception is dementia with Lewy bodies and Parkinson's disease dementia, where blood pressure control can be affected early, causing light-headedness on standing and falls.

If several of these changes have developed over months, a specialist assessment is worthwhile. I carry out a private memory assessment in clinic, at home (home visits within 50 miles of Sheffield) or by video consultation. No GP referral required.

Types of dementia

Dementia is an umbrella term. The type matters because it shapes treatment, what to expect and which risks to watch for.

  • Alzheimer's disease is the commonest type. It usually begins with recent memory and progresses gradually.
  • Vascular dementia results from reduced blood supply to the brain, through strokes or disease of the small blood vessels. Slowed thinking, difficulty planning and an uneven or stepwise course are typical.
  • Mixed dementia means Alzheimer's and vascular changes together, which is common in people in their 80s and 90s.
  • Dementia with Lewy bodies causes fluctuating alertness, visual hallucinations, acting out dreams during sleep, and Parkinson-like stiffness or slowness.
  • Parkinson's disease dementia describes thinking problems that develop in someone who has had Parkinson's disease for at least a year.
  • Frontotemporal dementia often starts before 65, with changes in personality, behaviour or language before memory.

Vascular and Lewy body dementia overlap with my work in TIA and stroke and Parkinson's disease, which is one reason I assess memory alongside physical health.

Can vascular dementia cause blackouts?

A blackout, meaning a brief loss of consciousness, is not a feature of vascular dementia itself. In someone with vascular disease it has other causes that need prompt investigation: a faint from low blood pressure or a heart rhythm problem, a seizure, or occasionally a stroke. A transient ischaemic attack usually causes weakness, numbness or speech disturbance rather than a blackout. Any sudden new symptom of this kind should be assessed urgently.

Is dizziness a feature of frontotemporal dementia?

Not typically. Frontotemporal dementia affects behaviour, personality and language. Dizziness in someone with this diagnosis usually has a separate cause, such as medicines, blood pressure or the inner ear, and should be assessed on its own merits. A small number of people with frontotemporal dementia develop movement problems that affect balance, which is different from dizziness.

Getting a diagnosis

A diagnosis rests on a careful history from the person and from someone who knows them well, cognitive testing, examination, blood tests and, when indicated, a brain scan. I explain each step in how dementia is diagnosed; the answers below are the short versions.

Can a geriatrician diagnose dementia?

Yes. Dementia is diagnosed by specialists in memory services, old age psychiatry, neurology and geriatric medicine, and NICE recommends that the diagnosis is made by a specialist dementia diagnostic service. As a consultant geriatrician I assess memory within a comprehensive geriatric assessment. That approach suits older people whose memory is affected by other conditions, medicines, mood, hearing or frailty.

Can dementia be diagnosed privately?

Yes. A private assessment follows the same clinical principles as an NHS memory service. No GP referral required. With your permission I send a full report to your GP, so that ongoing care can continue alongside the NHS. How treatment is started and continued after a private diagnosis is set out in my treatment guide.

Can a blood test detect memory loss?

Routine blood tests do not detect dementia, but they are an essential part of the assessment because they look for conditions that impair memory: low vitamin B12 or folate, an underactive thyroid, anaemia, kidney or liver problems, a high calcium level and poorly controlled diabetes. New blood tests for Alzheimer's proteins are promising but are not yet part of routine UK practice.

How can I get someone tested for dementia if they refuse?

An adult who has mental capacity is entitled to refuse, and pressure usually makes the refusal firmer. What often helps is presenting it as a general health check, linking it to something the person already accepts, such as a blood pressure or medicines review, choosing a calm moment, and involving a doctor they trust. You can write to the GP with your concerns even if the person does not want you involved in their care. A home assessment is sometimes accepted when a clinic appointment is not. The NHS page on being worried someone has dementia lists charity helplines that advise families in this position.

Treatment, and whether dementia can be slowed or reversed

Treatment has three aims: correct anything that is making memory worse, treat the symptoms of the dementia itself, and support the person and the family. Medicines and how they are monitored are covered in my treatment guide.

Can dementia be reversed if caught early?

Dementia caused by Alzheimer's disease, vascular disease or Lewy bodies cannot be reversed. However, some memory problems that resemble dementia, or make an existing dementia worse, improve when the cause is treated. These include medicines with sedative or anticholinergic effects, depression, delirium from infection, vitamin B12 deficiency, an underactive thyroid, sleep apnoea, heavy alcohol use, uncorrected hearing loss and, rarely, normal pressure hydrocephalus. Finding these is the main reason I look at the whole person, not only the memory score.

Is dementia treatable if caught early?

Treatment helps, although it does not stop the underlying disease. For mild to moderate Alzheimer's disease NICE recommends donepezil, galantamine or rivastigmine, and memantine is an option in moderate or severe disease. Some of these medicines are also used in dementia with Lewy bodies and Parkinson's disease dementia. NICE also recommends group cognitive stimulation therapy for mild to moderate dementia. An early diagnosis gives time to plan while the person can take a full part in decisions.

Is there a dementia cure breakthrough?

There is no cure. Two antibody treatments, lecanemab and donanemab, are licensed in the UK for early Alzheimer's disease. In trials they slowed decline modestly; they are given by regular infusion and need MRI monitoring because they can cause brain swelling and small bleeds. NICE has not recommended them for routine NHS use because it judged the benefit too small for the cost. They are suitable for only a minority of people with confirmed early Alzheimer's disease.

Do supplements work as a dementia treatment?

No vitamin, herbal remedy or brain-health supplement has been shown in good-quality trials to prevent dementia or slow it. The exception is correcting a proven deficiency, such as vitamin B12, which is why I check levels. Some supplements interact with prescribed medicines, so tell your doctor about anything you take.

Stages and how dementia progresses

Dementia is usually described in three stages: early (mild), middle (moderate) and late (severe). The stages overlap and the pace varies widely between people and between types. Another illness, a hospital admission or a fall often speeds decline, and a sudden deterioration should always be checked for a treatable cause.

How long does early stage Alzheimer's last?

There is no fixed length. The early stage often lasts a few years, but it can be shorter or considerably longer depending on age, general health and how early the diagnosis was made. It is the stage in which to make plans, including a Lasting Power of Attorney, while the person can take part fully.

What is the typical timeline for the middle stage of dementia?

The middle stage is usually the longest and often lasts several years. The person needs increasing help with dressing, washing and meals, may lose track of time and place, and changes in behaviour and sleep become more common. It is also the stage at which carers most need support, including a carer's assessment from the council.

What are the three stages of vascular dementia?

Vascular dementia is described in the same early, middle and late stages. The difference is the pattern: after strokes, decline can be stepwise, with sudden drops followed by periods of stability, whereas disease of the small blood vessels tends to cause a more gradual decline. Controlling blood pressure, cholesterol, diabetes and atrial fibrillation matters at every stage because it lowers the risk of further strokes.

At what stage of dementia do dizziness and losing balance appear?

In Alzheimer's disease, walking and balance usually stay fairly normal until the moderate to late stages. In vascular dementia, dementia with Lewy bodies and Parkinson's disease dementia, unsteadiness, slow walking and falls can appear early. Dizziness at any stage should not simply be put down to the dementia, because it often has a treatable cause such as blood pressure medicines. A falls assessment looks at these together.

Life expectancy and outlook

Life expectancy figures are averages drawn from large groups. They help with planning, but they cannot predict what will happen to one person.

What is the average life expectancy for someone diagnosed with dementia?

Alzheimer's Society gives these average survival times after diagnosis: around eight to ten years for Alzheimer's disease, around five years for vascular dementia, about six years for dementia with Lewy bodies, and about six to eight years for frontotemporal dementia. Survival is shorter when dementia is diagnosed at an older age or at a later stage, and in people with frailty or other serious illness. Many people die with dementia rather than because of it.

What is the life expectancy of people with dementia over 80?

It is shorter than for people diagnosed younger. In a large UK population study, median survival from the onset of dementia was about four and a half years overall, ranging from over ten years for onset in the late 60s to under four years for onset after 90. At this age, frailty, mobility and other illnesses often shape the outlook more than the dementia itself, which is why I discuss prognosis in the context of the whole person.

What is the average life expectancy for people with dementia and psychosis?

There is no reliable single figure. Hallucinations and delusions in dementia are associated with faster decline, and antipsychotic medicines, sometimes used to treat them, increase the risk of stroke and death in people with dementia. NICE therefore advises antipsychotics only when the person is at risk of harming themselves or others, or is severely distressed, at the lowest effective dose for the shortest time. In dementia with Lewy bodies, where visual hallucinations are common, some antipsychotics can cause severe reactions.

What is the average life expectancy for people with aggressive dementia?

'Aggressive' is used in two ways. If it means a rapidly progressive dementia, with decline over weeks or months, the causes include prion disease such as Creutzfeldt-Jakob disease, autoimmune encephalitis and other conditions, some of them treatable; this needs urgent specialist assessment, and the outlook depends on the cause. If it means aggressive behaviour, that is a symptom, often driven by pain, fear, infection or misunderstanding, and it does not by itself indicate a particular life expectancy.

Changes in behaviour, mood and sleep

Changes in behaviour are part of dementia, but a sudden change over hours or days is different. It is more often delirium, brought on by infection, pain, constipation, dehydration or a new medicine, and it needs prompt medical review. NICE advises that when delirium cannot be told apart from dementia, delirium should be treated first.

What are four common behaviours that people with dementia often exhibit?

Four that families often describe are agitation and restlessness, including walking about; repeating the same question or action; disturbed sleep, with wakefulness at night and drowsiness by day; and irritability or aggression. Increased confusion in the late afternoon and evening, often called sundowning, is also common. Each is usually a response to something, such as pain, boredom, noise, fear or a need the person cannot put into words, and finding the trigger helps more than medicine.

What is the denial stage of dementia?

It is not a formal stage. Many people with dementia genuinely do not recognise their difficulties, because the illness affects the parts of the brain that support self-awareness; the medical term is anosognosia. Others are aware but frightened. Arguing about the diagnosis rarely helps. Concentrate on practical help and on what the person can still do, and keep the doctor informed.

Can dementia cause an explosive temper?

Yes. Irritability and sudden anger are common, particularly when the frontal lobes are affected, as in frontotemporal dementia, and in vascular dementia. Frequent triggers are pain, tiredness, feeling rushed or corrected, hearing loss and unfamiliar surroundings. A new temper in someone previously calm should prompt a check for infection, pain or side effects of medicines. Medicines to calm behaviour are a last resort.

Is there a connection between vascular dementia and excessive sleeping?

Yes. Sleeping more is common in vascular dementia, and in dementia generally as it progresses. It can also come from medicines such as sleeping tablets, some antidepressants, antipsychotics and strong painkillers, and from depression, sleep apnoea, infection or a new stroke. A sudden increase in sleepiness needs medical review; a gradual increase over months is more often the dementia itself.

Should you let someone with dementia sleep all day?

In the early and middle stages, a daily rhythm helps: getting up at a regular time, daylight, some activity and short naps rather than sleeping all day, which also improves sleep at night. In the late stage, sleeping for most of the day is part of the illness and repeatedly waking the person does not help. If drowsiness is new or sudden, or the person is hard to rouse, seek medical advice the same day.

Are clenched hands a common symptom of dementia?

Not in the early stages. In advanced dementia, stiff, tightly flexed hands and limbs (contractures) can develop as mobility declines. Stiffness earlier in the illness points to parkinsonism, as in dementia with Lewy bodies or Parkinson's disease dementia; I describe the early signs of Parkinson's disease in a separate article.

Living with dementia: safety, care and support

Money, legal and benefit questions belong with the official sources linked below and with independent advisers. I signpost them here; I do not give financial or legal advice.

I was diagnosed with dementia. What should I do now?

Take time to absorb it, then work through a few practical steps. Ask which type of dementia you have and which treatments are suitable. Make a Lasting Power of Attorney for health and welfare and for property and finances while you can do so yourself. The law requires you to tell the DVLA, and you should also tell your car insurer. Have your medicines reviewed, and stay active and socially connected.

My husband has dementia: what help can I get?

Ask the council for a needs assessment for him and a carer's assessment for you; both are free. Check benefits: Attendance Allowance for people over State Pension age is not means-tested, and a council tax discount may apply for severe mental impairment. The GP can arrange community services such as occupational therapy, and Alzheimer's Society and Dementia UK run advice lines and local support.

What can I do to get support for memory loss?

Start with your GP, who can check for common causes and refer to the local NHS memory service, or arrange a private specialist assessment. After a diagnosis, support comes from several directions: the memory service or specialist, the council's adult social care team, and charities that run memory cafés, carers' groups and helplines.

When should a person with dementia stop living alone?

There is no single point. Signs that living alone is no longer safe include leaving the cooker on, getting lost outside, not eating or drinking enough, missed or doubled medicines, falls with long lies on the floor, falling for scams, and distress at night. Before a move, more support at home often helps: carers, telecare such as falls alarms and cooker sensors, meals, day services and medication aids. A council needs assessment is the starting point, and the person's own wishes count even when they can no longer make the decision themselves.

Are people with dementia entitled to free care?

Not automatically. NHS treatment is free. Social care, meaning help at home or a care home place, is arranged by the council after a needs assessment and is means-tested. If a person's needs are primarily health needs, they may qualify for NHS continuing healthcare, which is fully funded and decided by an assessment of needs rather than by the diagnosis. Independent advice before paying for care is worthwhile.

How do I protect my assets when my husband has dementia?

This is a question for a solicitor or a specialist later-life financial adviser, not a doctor. The step most families need is a Lasting Power of Attorney for property and financial affairs, made while the person still has capacity. If capacity has already been lost and there is no attorney, a relative can apply to the Court of Protection to act as a deputy.

Is Alzheimer's a disability in the UK?

Usually, yes. Under the Equality Act 2010, a mental impairment with a substantial and long-term effect on everyday activities counts as a disability, and progressive conditions can qualify. That gives protection against discrimination, including a right to reasonable adjustments at work. Disability benefits depend on care needs rather than on the diagnosis.

What is the 90 second rule for dementia?

It is not a clinical term. It comes from the neuroanatomist Jill Bolte Taylor, who described the physical surge of an emotion as passing within about 90 seconds unless something triggers it again. Carers use it as a reminder: when the person is upset, pause, stay calm, avoid arguing or correcting, and let the feeling settle before gently redirecting. It has not been studied in dementia, but it matches good communication practice.

What are dementia friendly communities in the UK?

They are towns, organisations and businesses that have committed, through Alzheimer's Society's dementia-friendly programme, to making everyday life easier for people with dementia: staff who understand the condition, clear signs, and services that allow extra time.

Causes, risk and prevention

Age is the strongest risk factor, and genes play a part, but many risk factors can be changed. The 2024 Lancet Commission on dementia identified 14: less education in early life, hearing loss, high LDL cholesterol, depression, head injury, physical inactivity, smoking, diabetes, high blood pressure, obesity, excess alcohol, social isolation, air pollution and untreated vision loss. It estimated that nearly half of dementia cases could in theory be prevented or delayed by addressing them. For older adults the practical priorities are blood pressure, hearing and vision correction, activity and social contact.

Is vertigo the start of dementia?

No. Vertigo, a spinning sensation, almost always comes from the inner ear or, less often, the brain's balance pathways. It is not an early sign of dementia. It does matter in an older person with memory problems, because it raises the risk of falls. The commonest cause in older people is explained in BPPV in older people, and I assess persistent symptoms in a dizziness assessment.

Arranging a specialist assessment

If you recognise several of the changes in this guide, or a diagnosis has been made and questions remain, I can help. I assess memory as part of a whole-person review in clinic in Sheffield, at home within 50 miles of Sheffield, or by video. No GP referral required. Details of the private memory assessment, home visits and video consultations are on their own pages, fees are on the fees page, and you can contact me with questions.

References