Dementia is not what ageing does to everybody. It is what specific diseases do to some people — and a few of the things that look exactly like it are curable.
Around 57 million people live with dementia and most of them waited years for a name for it, because the first symptoms are indistinguishable from being tired, sad, distracted or seventy. That delay costs more than dignity: depression, thyroid disease, vitamin B12 deficiency, sleep apnoea, alcohol and half a dozen ordinary medications produce the same picture and can be treated, and a sudden confusion over hours or days is usually an infection rather than dementia — a medical emergency that is routinely mistaken for “he has gone downhill.” This page is about telling ageing from disease, knowing which mimics to rule out, why a diagnosis is worth having even where no cure exists, and how to talk to someone whose memory has stopped agreeing with yours.
57Mpeople living with dementia worldwide
~45%of risk is linked to factors you can act on
Hoursconfusion that fast is delirium, not dementia
Forgetting a name and remembering it in the shower is ageing. Asking the same question three times in one conversation, or getting lost on a route you have driven for thirty years, is worth an appointment — not because it is certainly dementia, but because several of the things it could be are fixable.
Ageing, or worth an appointment?
Sixteen things that actually happen. Put each one where you think it belongs, then have the sort graded — the explanations are the point, not the score. Nothing here diagnoses anybody: it is the shape of the distinction that clinicians use.
Nothing is saved and nothing is sent anywhere. No names, no details — this is only about which pile a behaviour belongs in.
What it actually is
Dementia is not a disease. It is a description — a loss of thinking, memory, language or judgment big enough to interfere with daily life — caused by one of several diseases that damage the brain in different places, which is why two people with the same word on their file behave nothing alike.
Alzheimer’s disease is the commonest, roughly two thirds of cases. It usually starts with recent memory and orientation, and progresses slowly and steadily over years.
Vascular dementia comes from damaged blood supply — strokes large or tiny. It often arrives in steps rather than a slope, hits planning and speed of thinking early, and is the type most influenced by blood pressure, diabetes and smoking.
Lewy body dementia brings fluctuating alertness, vivid visual hallucinations, acting out dreams, and stiffness or slowness like Parkinson’s. It matters enormously to identify, because certain antipsychotic drugs can cause severe harm in these patients.
Frontotemporal dementia often starts young — in the fifties, sometimes forties — and starts with personality, behaviour or language rather than memory. Families are frequently told it is depression, a midlife crisis or a difficult marriage for years.
Mixed causes are normal, especially over eighty. Most brains at that age show more than one process at once.
The myth that costs the most time: that dementia always starts with memory. It can start with words that will not come, with getting lost in a familiar car park, with losing the ability to read a bank statement, with apathy that looks like laziness, or with behaviour that looks like a personality change. If something is clearly different from the person you have known for decades, that is the signal — whichever ability changed.
The things that look like it and are not
This is the part that justifies the appointment on its own. A meaningful minority of people sent for memory assessment have something else, and some of those are entirely reversible.
Depression in later life impairs concentration and memory so convincingly that it used to be called pseudodementia. It is treatable, and it also often accompanies real dementia — treating it improves life either way.
Vitamin B12 or folate deficiency, and thyroid disease. Cheap blood tests, ordinary treatments, and a genuine cause of confusion that is missed when nobody looks.
Medication. Anticholinergics, sedatives, benzodiazepines, some bladder and allergy drugs, and simply too many drugs at once all cloud thinking in older people. A structured medication review is one of the highest-yield things a doctor can do.
Alcohol, which causes its own lasting damage and is under-reported by almost everybody. Reducing it can recover real ground.
Hearing and vision loss. Someone who cannot hear the question answers it wrongly and looks confused. Untreated hearing loss is also one of the largest modifiable risks for dementia itself — hearing aids are not a vanity item.
Sleep apnoea, which starves the brain of oxygen all night and produces daytime fog that looks like early dementia. Treatable, and often obvious once somebody asks about snoring.
Structural causes: a slow bleed under the skull after a fall, normal-pressure hydrocephalus (the classic trio is walking trouble, incontinence and confusion), or a tumour. Some of these are surgically treatable, which is why scans exist.
Confusion that arrives in hours or days is delirium, not dementia, and it is a medical emergency. In older people a urinary or chest infection, dehydration, constipation, pain, a new drug or alcohol withdrawal can produce sudden disorientation, hallucinations or drowsiness. It is common, it is often reversible, and the mortality is significant when it is dismissed as decline. If someone is suddenly much more confused than they were yesterday, that is a same-day call to a doctor — or the emergency number if they are drowsy, unrousable or very unwell. Delirium on top of dementia is also extremely common and often the first sign of a treatable infection.
Why get a diagnosis, if there is no cure
The most understandable reason people avoid the appointment is that a name changes nothing. It changes a surprising amount.
It finds the treatable things. The mimics above, plus depression, pain, hearing loss and drug side effects, are all found by the same assessment. Many people leave with something to fix.
It gets the type right. Lewy body dementia in particular changes which drugs are dangerous, and vascular disease changes what to treat aggressively.
It buys the window in which the person can still decide. Powers of attorney, financial arrangements, an advance decision about future care, and simply saying what they want — all of it requires capacity, and capacity is a closing door.
It unlocks the practical scaffolding: nurses, occupational therapists, day services, carer support, benefits or allowances, adaptations at home, and in some countries early-stage treatments and trials that are only available to people diagnosed early.
It replaces blame with an explanation. Families spend years being angry at someone for being difficult, careless or cruel. The diagnosis reframes every one of those months, which is worth more than people expect.
It lets the person speak for themselves while they can, about the things nobody else can decide: where they want to be, what treatment they would refuse, who they trust with what.
Getting to the appointment. Write down examples with dates before you go — specific incidents beat “his memory is bad.” Bring the medication list, including anything bought over the counter. Ask for hearing and vision to be checked as part of it. And if the person refuses to go, a visit framed around something else — blood pressure, a medication review, a check-up — is a legitimate route in, because the same tests get done.
How to talk to someone whose memory has stopped agreeing with yours
Almost every instinct is wrong here, and almost all of the damage is repairable in one conversation once you know the swap. The rule underneath all of it: you are answering the feeling, not the fact.
“Don’t you remember? We talked about this yesterday.”
Instead: answer the question again as if it were the first time. They are not being lazy; the recording was never made, so being told it exists is only frightening.
“Mum, your mother died in 1998.”
Instead: “You’re missing her. Tell me about her.” Correcting a false belief re-inflicts a bereavement several times a week and changes nothing. Answer what the words are actually about.
“Do you know who I am?”
Instead: “Hello Dad, it’s Anna.” Never test someone. Introduce yourself, from the front, with your name, and let recognition be optional.
“I want to go home” — answered with “you are home.”
Instead: “Tell me about home.” Home usually means safe, needed, and among your own people. It is a request for a feeling, not an address.
Three questions at once, from behind, with the television on.
Instead: one thing at a time, face to face, background noise off, and a wait of several seconds. Most apparent incomprehension is just a slower processing speed meeting an impatient room.
“You have already had your tablets, I told you twice.”
Instead: blame the situation, not the person — “the box is a bit confusing, let’s look together.” Preserving their dignity is not a kindness you add on top; it is the thing that keeps them cooperating with you.
On lying. Blunt correction is cruel and pointless; elaborate deception erodes trust and eventually gets caught. What works in between is meeting the emotion honestly without arguing about the fact — and, when a direct answer would only wound, redirecting to something true and immediate. Care teams call it therapeutic honesty, and the test is simple: would you be comfortable if the person understood exactly what you did and why?
Behaviour is a message, usually about something ordinary
What gets labelled “challenging behaviour” is nearly always communication by someone who has lost the words for it. The first question is never psychiatric.
Pain. Untreated arthritis, toothache, an ulcer, a full bladder or constipation cause a large share of sudden agitation. Someone who cannot say “my hip hurts” shouts instead.
Infection. New agitation or confusion, especially with a fever or a change in urine, means a doctor today — see delirium above.
Too much or too little going on. Noise, crowds, mirrors, television arguments mistaken for real ones, or a whole day with nothing to do all produce distress.
Late-afternoon restlessness is common enough to have a name. It responds to light, a calmer routine, less caffeine, a walk earlier in the day and lower expectations of evening tasks.
Repetition is usually anxiety looking for reassurance. A written note answering the recurring question, left where they look, often works better than the twentieth verbal answer.
Refusing to wash or change is frequently fear of the bathroom, cold, or humiliation at being undressed by an adult child rather than stubbornness. Warmth, one step at a time and preserved modesty solve much of it.
Antipsychotic drugs are a last resort, not a first response: they increase the risk of stroke and death in people with dementia, and are actively dangerous in Lewy body dementia. If they are proposed, ask what is being ruled out first and when the drug will be reviewed.
The practical things, while there is still time
Legal authority, early. A lasting power of attorney (or your country’s equivalent) for both finances and health, made while the person clearly has capacity, is the single most useful document in this whole illness. Made too late, it becomes a court process instead.
Money protections. Automatic bill payments, a spending-alert on the account, a trusted-contact registered with the bank, and removing the pressure of doorstep and telephone salespeople. People with dementia are targeted deliberately, and losing savings is common and preventable.
Driving. A diagnosis usually carries a legal duty to inform the licensing authority and the insurer, and driving is not automatically over — in many places an assessment decides. What is never acceptable is a family quietly waiting to see. Hidden keys and small confusions cost strangers their lives.
Write down the person, not just the illness. A one-page life story — names, work, music, faith, what they hate, how they take their tea — travels with them to every hospital and care setting and changes the quality of care they get from strangers.
Home, adjusted rather than rebuilt: good light, contrasting colours on toilet seats and door frames, labels, a clock showing day and date, removing rugs and mirrors that confuse, and a key-safe for carers. An occupational therapist does this better than a shop.
Prepare for the walk that goes wrong. Roughly three in five people with dementia will get lost at some point, and the first hours matter. Keep a current photo, sew or clip identification with a phone number into the coats they actually wear, tell two neighbours and the local shop, consider a GPS device or a location-sharing phone, and keep a list of the places they might head for — old addresses, old workplaces, a childhood town.
Say the difficult things now, while both sides can. What they want at the end, what they fear, what they would refuse, whether they mind a care home if it comes to that. Doing it early means the family is later remembering a decision instead of guessing at one.
If they are missing, call the police straight away and say the word dementia. There is no waiting period, and this is not an overreaction: people with dementia who go missing are at real risk from cold, traffic and water, and the search is far more effective in the first hours. Give the police the photo, the places they might be heading, what they were wearing, and whether they usually travel on foot or by bus. Families routinely apologise for calling — police forces would much rather come out early.
What actually reduces the risk
Dementia is not simply fate. A large share of cases — the best current estimate is around 45% — is associated with factors that can be changed, and midlife is where most of the leverage is. None of this is a guarantee, and nobody with dementia caused it by living wrong.
Evidence behind them
Treat hearing loss — get the test, wear the aids
Blood pressure controlled from your forties onward
Not smoking, and less alcohol
Physical activity most days, of any kind you will actually do
Diabetes, cholesterol and obesity managed
Treating depression, and staying socially connected
Protecting your head — helmets, and preventing falls
Correcting vision loss; getting decent sleep
Not worth your money
Brain-training apps as insurance — you get better at the app
Coconut oil, silver, chelation and detox regimes
Most supplements, without a deficiency to correct
Anything sold with the words reverse and cure together
Private “memory screening” kiosks that sell you the answer
Waiting for a blood test to be perfect before doing the eight things on the left
“Will I get it?” Almost always, the answer is that this is not straightforwardly inherited. The great majority of dementia is not caused by a single faulty gene; the rare families where it is usually show a striking pattern — several relatives affected young, across generations — and they need a genetics clinic rather than a search engine. Common risk genes shift the odds without deciding anything, which is why consumer DNA tests mostly deliver anxiety with no action attached. If your family history worries you, the productive move is the list on the left, starting in your forties.
The connection nobody mentions: hearing aids, treated blood pressure and company are boring, cheap and better supported than anything you can buy in a bottle. If you do one thing after reading this page, book the hearing test — for yourself, or for the person you are worried about.
The half of this that happens to you
Carer depression and exhaustion are the rule, not a weakness. A third to a half of family carers reach clinical levels. Your own doctor needs to know you are caring for someone — it changes what help exists for you.
Grief starts long before the death. Mourning someone who is still alive is a recognised phenomenon, and it does not mean you have given up on them.
Ask for a carer’s assessment if your country has one, and take respite before you need it rather than after you break. Every service you delay asking for takes longer to arrive than you expect.
Anger is normal and does not make you a bad person. The repetition wears down love in everybody; what matters is having somewhere to put it that is not the person.
A care home is not a failure. Round-the-clock care is a job for a team, and the decision usually comes years later than it should have. Guilt is not evidence of a wrong choice.
Let people help concretely. Most offers of help die from vagueness — answer them with a specific task: Tuesday afternoons, the shopping, sitting with him for two hours so I can sleep.
Later on
Dementia is a terminal illness, which is rarely said out loud. Recognising that unlocks palliative care, and people who get it earlier are more comfortable and less often dragged through futile hospital admissions.
Eating and drinking change. Difficulty swallowing is part of the late disease. Feeding tubes do not prolong life or prevent pneumonia in advanced dementia; careful hand-feeding of what the person enjoys, for as long as they enjoy it, is the recommended approach.
Hospital is not automatically the right place. Admissions frequently cause delirium, falls and decline. For some late problems, treatment at home with support is both kinder and more effective — a conversation worth having in advance.
Infections and pneumonia are the usual final path, and the question “would we treat this if it happened again next month?” is a legitimate thing for a family to ask a doctor.
Comfort is measurable: pain relief, mouth care, warmth, calm, familiar voices and music. Music and touch keep reaching people long after language has gone.
The person is still there for far longer than the deficits suggest. Recognition of a voice, a hand, a hymn or a smell survives when names do not.
The drill: 16 decisions
Sixteen ordinary moments — a repeated question, a missed appointment, a set of car keys, a phone call from a bank. Most have an instinctive answer that makes things worse. Pick your move; every answer explains why.
The card
Print it for the fridge, or for whoever comes to help.
DEMENTIA — THE THINGS THAT HELP
SEE A DOCTOR ABOUT
Repeating the same question in one conversation; getting lost on familiar routes
Trouble with money, recipes, appointments; words that will not come
Personality or behaviour change; apathy that is new
Sudden confusion over hours or days = delirium. Same-day call