Dementia Worldwide: 57 Million People and the Gaps in Their Care

The World Health Organization estimates that 57 million people were living with dementia worldwide in 2021^[1], and dementia was the fifth leading cause of death in the world in 2023^[2]. Yet in the typical country that can measure it, only about a quarter of people with dementia have a recorded diagnosis, and much of their care is given unpaid by family and friends^[3][4].

Behind each figure are people getting on with their lives: someone noticing that familiar names are slipping, a partner quietly taking over the bills, a family trying to find out who to ask for help. The evidence collected in this library shows that what happens next depends less on the condition itself than on where a person lives, how much money and schooling they have had, and whether services are there when they are needed. This overview brings the main findings together and points to the study in the dementia research library that covers each one in depth.

More people are living with dementia, even where the risk at each age is falling

WHO puts the number of people living with dementia worldwide at 57 million in 2021, with nearly 10 million new cases every year^[1]. These are modelled estimates, and other models give somewhat different totals: the cost study described below worked from 55.2 million people for 2019^[4]. What every estimate agrees on is direction. As populations grow and live longer, the number of people living with dementia rises. Our study of prevalence and projections sets out how the main forecasts are made and why they differ.

The more hopeful finding is about risk, not numbers. Pooling seven population cohorts in the United States and Europe, the Alzheimer Cohorts Consortium found that the incidence rate of dementia fell by 13% per calendar decade between 1988 and 2015, more in men (24%) than in women (8%)^[5]. The authors caution that this needs testing in “geographically and ethnically diverse populations”, because almost all the evidence comes from high-income countries^[5].

That fall in age-specific risk is one reason the Lancet Commission on dementia argues that much dementia could be prevented or delayed. Its 2024 report names 14 potentially modifiable risk factors, adding uncorrected vision loss and high LDL cholesterol to the 12 it named in 2020, and estimates that together they account for “nearly half of dementias”^[6]. That is a modelled population estimate of what might be achieved if the risks were removed, not a statement that any person’s dementia was caused by them or could have been avoided. Our study of the Lancet risk factors explains how the estimate is built, and hearing and sight looks at two of the factors in detail.

Dementia is not only a condition of later life. A meta-analysis of 95 studies estimated that 3.9 million people aged 30 to 64 are living with young-onset dementia worldwide^[7]; WHO puts young-onset dementia at up to 9% of cases^[1]. Their particular needs, from work to family life, are the subject of our study of young-onset dementia.

Where countries can measure it, the typical diagnostic rate is one in four, and support after diagnosis is patchy

A diagnosis is the door to almost everything else: information, treatment, support for carers, planning for the future. In 2024 WHO reported that only 37 of the 78 countries taking part in its Global Dementia Observatory could report a dementia diagnostic rate at all. Among those that could, the median was 26%: 62% in 17 high-income countries and 6% in 14 low- and middle-income countries^[3]. WHO’s global action plan had asked for at least half of countries to diagnose at least half of the people estimated to have dementia^[3]. A diagnostic rate is usually recorded diagnoses divided by a modelled estimate of how many people are expected to have dementia, so it is only as good as both halves; our studies of diagnosis rates and how dementia is counted explain why national figures are not directly comparable.

For those who are diagnosed, the road is long. A 2025 meta-analysis of 13 studies found an average of 3.5 years between the first symptoms and a diagnosis, and 4.1 years for young-onset dementia^[8]. Our study of waiting for a diagnosis looks at where those years go, and dementia subtypes at how often records name the type of dementia at all.

A diagnosis also does not guarantee support. In Alzheimer’s Disease International’s 2022 global survey, 58% of the 365 people living with dementia who responded, from 41 countries, said they had no key worker or named professional to help them find their way through services, and 64% had no personalised care plan^[9]. This was a self-selected survey rather than a representative sample, but it falls well short of what guidelines in many countries promise, and it matches what our study of post-diagnostic support finds. Newer medicines for early Alzheimer’s disease have raised the stakes of an early, accurate diagnosis; their modest benefits and real risks are covered in new treatments.

Hospitals and care homes are often not built around the people with dementia who use them

People with dementia go into hospital more often than other people of the same age. Pooling 34 studies of 277,432 people with dementia, mostly from the United States and Europe, one meta-analysis found that people with dementia living in the community had 1.42 times the risk of hospital admission of people without dementia, after allowing for age, sex and physical illness^[10]. Once there, delirium is common: across 81 studies, 48.9% of hospitalised older people with dementia also had delirium, a sudden and usually temporary confusion; compared with dementia alone, it was linked to longer stays, more moves into care homes and higher mortality^[11]. Our studies of hospital admissions, emergency admissions and delirium and falls follow these journeys in detail.

In many countries, care homes have become in large part homes for people with dementia. In Canada, 69% of residents of long-term care homes had dementia in 2015–16^[12]. Yet care is not always shaped around them. In those same Canadian homes, 27% of residents with dementia were given an antipsychotic without a diagnosis of psychosis, a measure the Canadian Institute for Health Information treats as potentially inappropriate use, against 11% of residents without dementia; CIHI reports that policy and training changes have since reduced such use^[12]. During the COVID-19 pandemic, a study of 857,238 people with dementia aged 65 and over in six countries (France, Germany, Italy, South Korea, the UK and the US) found that antipsychotic prescribing rates rose in databases from every one of them^[13].

These are failures of systems, staffing and training. See care homes, antipsychotic prescribing, workforce training and COVID-19 deaths for the fuller picture.

Half the cost of dementia is carried by unpaid carers

Dementia cost the world an estimated US$1,313.4 billion in 2019. Only 16% of that was medical care; 34% was social and long-term care, and 50% was the value of unpaid care given by family and friends^[4]. The same modelled estimate found that 61% of people with dementia live in low- and middle-income countries, while 74% of the costs occur in high-income countries^[4]. The authors describe building long-term care in low- and middle-income countries as “a great challenge”. Our study of the cost of care shows how differently countries share these costs between public budgets and households.

Most of that unpaid care is given by women: WHO reports that women provide 70% of care hours for people living with dementia^[1]. In the United States alone, the Alzheimer’s Association estimates that nearly 13 million people provide unpaid care for someone with Alzheimer’s or another dementia, giving more than 19 billion hours of care in 2025^[14]. The strain shows in carers’ own health. A meta-analysis of 17 studies covering 10,825 carers of people with Alzheimer’s disease found depression in 34.0% and anxiety in 43.6%^[15].

Support for carers is far from universal. In 2024, services for dementia carers were available in 89% of high-income countries taking part in WHO’s Observatory but only 35% of low- and middle-income ones^[3]. The strain carers describe tracks gaps in that support, not the person they care for. See unpaid carers, carers’ health and, for people with dementia who have no one living with them, living alone.

Dementia does not fall evenly

Across the evidence in this library, the same pattern recurs: the people with the fewest resources face the highest risk and the thinnest services. A meta-analysis of 39 prospective studies covering almost 1.5 million people found that people of low socioeconomic status had 1.40 times the risk of all-cause dementia of those of high status^[16]. These are associations, shaped by education, income and lifelong health, not proof that poverty alone causes dementia. In a study of 274,283 members of one US health plan, followed from 2000 to 2013, dementia incidence ranged from 15.2 per 1,000 person-years among Asian-American members to 26.6 among African-American members, and the authors note that rates “varied over 60% between groups”^[17].

Geography matters as much as social position. Among the countries reporting to WHO in 2024, only 6 of 43 low- and middle-income countries said community dementia services reached rural areas, compared with 26 of 35 high-income countries^[3]. Sex matters too: in WHO’s estimates, 66% of dementia deaths worldwide are among women^[2], who also give most of the unpaid care^[1].

The library looks at each of these gaps separately: deprivation, ethnicity, rural and remote areas, regional variation within countries, differences between countries, learning disability and Down syndrome, and LGBTQ+ older people.

Dementia is now one of the main causes of death, though countries count it differently

WHO’s Global Health Estimates ranked Alzheimer’s disease and other dementias as the fifth leading cause of death worldwide in 2023, with 2.1 million deaths, and the third in high-income countries, up from seventh in 2000^[2]. In some countries it is now first. In England and Wales, dementia and Alzheimer’s disease were the leading cause of death in 2025, with 72,272 deaths registered, 12.7% of all deaths, and 16.5% of deaths among women against 9.1% among men^[18]. In Australia, dementia including Alzheimer’s disease was the leading cause of death in 2024, at 9.4% of deaths^[19].

These figures count dementia as the underlying cause of death, and they are sensitive to how doctors certify deaths and how statisticians code them, which varies between countries and over time. Rising counts can reflect population aging and changes in recording as well as changes in risk, so they cannot be read as a straight measure of rising risk. Our study of dementia as a leading cause of death unpicks those effects, and end-of-life care asks whether people with dementia receive the palliative care that a condition people die from should bring.

What the evidence asks of us

In 2017 the World Health Assembly endorsed a global action plan on dementia^[1]. By 2024, WHO’s own progress report concluded that “no target is on track to be met by 2025”: only 26% of countries (50 of 194) had a national dementia plan, against a target of 75%^[3]. The plan has since been extended to 2031^[1]. The studies in this library point to how that time should be used:

• Count, so the gaps can be seen. Fewer than half of the countries in WHO’s Observatory could report a diagnostic rate^[3]. Every country can work towards publishing one, along with data on waits, support after diagnosis and care.
• Make diagnosis timely and worth having. Years between first symptoms and diagnosis^[8], and a diagnosis too often followed by no named professional and no care plan^[9], are gaps in services, and services can close them.
• Back unpaid carers with real support. Families already give half the value of dementia care^[4]. Carer services that exist in most high-income countries but only about a third of low- and middle-income ones^[3] should be within reach everywhere.
• Design hospitals and care homes for the people who use them. With delirium affecting about half of hospitalised older people with dementia^[11] and potentially inappropriate antipsychotic use common in care homes (Canada, 2015–16)^[12], dementia care is core business, not a specialism.
• Take prevention and fairness seriously together. If nearly half of dementia is linked to modifiable factors^[6], and risk is highest where resources are lowest^[16], public health action on education, hearing, blood pressure and the rest is also action on inequality. Our studies of research funding and dementia-friendly services look at two other levers.

Language: this piece uses person-first language ("people living with dementia", "people with dementia"), as most dementia organisations and people with lived experience prefer, and uses clinical terms such as "Alzheimer's disease" or "mild cognitive impairment" only where a study, dataset or diagnosis refers to that specific condition.

Why we're publishing this

People living with dementia, their families and the organisations that support them make their case every day, often against the assumption that little can be done. The evidence says otherwise. Much of what shapes life with dementia, from whether a diagnosis comes at all to whether a carer gets a break, depends on decisions that services and governments make. This overview, and the library it opens, gathers the best published figures from around the world in one place, with every number traced to its source, so that charities, carers’ groups and campaigners can use them with confidence.

How to read this data

The figures here come from very different kinds of evidence, and they answer different questions:

Each figure carries its country, period and population. Figures from different countries or methods are set side by side to show the range of what is known, not as like-for-like comparisons or trends. Much of the evidence comes from high-income countries, while most people with dementia live elsewhere^[1]; where we found no data for a region, that is a gap in what we could find, not proof that a problem is absent.

Use this data

Free to cite with attribution to Understanding Aging. Charities, carers' groups, campaigners and journalists are welcome to reuse these figures and charts. For the underlying figures as a spreadsheet, get in touch.

Important: This article summarises published research and statistics for general information. It is not medical, care or financial advice and cannot be used to diagnose, treat or predict anything about an individual. If you have concerns about your own or someone else's memory or health, please speak to a GP or another qualified health professional.

Sources

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