Alzheimer's in the United States is most prevalent in the South and the East.

Alzheimer's disease is the leading cause of dementia and risks rise after age 65

Read this primer about Alzheimer's disease and learn what factors increase the risk of this form of dementia, including genetics, being a woman, and health conditions, including high blood pressure.

Five to ten percent of Alzheimer's cases are early-onset

Early-onset Alzheimer’s typically emerges around 40 to 50 years of age, with devastating effects. This video follows Brian, diagnosed with the disease at age 54, as he travels the country as an advocate for research and discusses the progressive mental fog of Alzheimer’s.

Explore this 1440 Original video offering a primer on Alzheimer's disease and what's known about its incidence, causes, and more.

See MS prevalence by region in the United States

This map underscores that people in the northeastern United States have more cases of the disease as compared to the south, west, and midwest. On an individual level, these numbers may still differ based on genetic makeup and other factors irrespective of where people live.

Early-onset Alzheimer's can appear as early as age 30, but estimates of its prevalence remain uncertain.

Millions of aging Americans are facing dementia or cognitive impairment—alone

An estimated 4.3 million people aged 55 or older who have cognitive impairment or dementia live alone in the US. The individuals facing these challenges are more likely to be women, people of color, and to generally be poorer and less educated than other older adults who are also living alone.

Poor sleep increases the risk of developing Alzheimer's, and a main reason appears to be that the brain disposes of toxic protein buildup during high-quality sleep.

Medical experts warn that completing genetic testing for Alzheimer's can be fraught, in part because there's a shortage of genetic counselors to help navigate the findings and their potential implications.

Multiple genes are associated with Alzheimer's risk, but one particularly well-known disease-associated gene is apolipoprotein E (APOE), which typically encodes a protein that helps carry cholesterol and other fats in the bloodstream.

Does our fear of Alzheimer's create stigma around its treatment?

Surveys suggest our fear of Alzheimer's as a disease outranks that of heart disease and cancer. This piece argues our fear of aging and the slipping away of our mental capacities make it more difficult to treat Alzheimer's compassionately.

How Alzheimer's disease becomes fatal

Despite more than 100,000 people with Alzheimer's dying each year, the specific cause of death is not the disease itself. Often, secondary diseases arise from complications with the disease, including pneumonia, severe falls, malnutrition, or infection. Read more about the range of complications caused by Alzheimer's here.

"Plaques" and "tangles" are top potential causes of Alzheimer's—but questions remain

The exact causes of Alzheimer's—and how to treat it—continue to be the subject of intense research. Two leading factors are amyloid beta plaques and tau protein tangles, which effectively pile up in the brain and interfere with neurons and cause cell death, which manifests as memory loss and other symptoms.

Minorities are largely underrepresented in medical research, which compromises our understanding of how conditions and treatments may affect various populations, but recent efforts, like the African Ancestry Neuroscience Research Initiative and new genome research studies, are seeking to close that gap.

America's financial burden from dementia in 2025 was $781 billion

That figure, calculated by researchers at the University of Southern California, includes medical and long-term care costs, unpaid family and friend caretaking, lost productivity for patients and their families, and the economic loss in quality of life for patients and their families. In 2025, they estimate there were 5.6 million people living with dementia.

Ultraprocessed foods are linked with a 58% elevated risk of developing dementia.

Alzheimer's brain changes may begin years before symptoms appear.

There are two FDA-approved blood tests that may detect early Alzheimer's disease.

Visualize the difference between a healthy brain and one with Alzheimer's.

Scientists are reevaluating the causes of Alzheimer's beyond the amyloid hypothesis after numerous experimental drugs designed to target that theory have failed.

Alzheimer's can cause significant brain shrinkage in the affected brain regions, including the hippocampus.

The first identification of Alzheimer's was made in 1906.

Stroke risk doubles each decade after age 55

While age is the greatest risk factor, genetics, diet, and overall health play a prominent role in determining individual stroke risk. Prevention focuses heavily on modifiable risk factors. High blood pressure is the single most important controllable risk factor, contributing to both types of stroke.

Read a study about racial differences in Lyme disease diagnosis

The research published in September 2025 examined differences in Lyme disease diagnosis among Medicaid and Medicare beneficiaries using data from 2016 to 2021. It notes that though US Lyme disease surveillance data indicates more than 90% of diagnosed Lyme cases are among white people, people of color—particularly those who identify as Black or African American—have higher rates of more severe disease of Lyme, with symptoms including arthritis and neurologic impacts.

See how anxiety disorder rates vary across 200+ countries, with Portugal, Malta, Brazil, and Iran reporting the highest burdens.

Age-related macular degeneration is the primary cause of blindness in older Americans.

Genetic blood test offers an estimated clock on when Alzheimer's symptoms may appear

The 2026 research finding from researchers at Washington University School of Medicine in St. Louis—if validated in broader populations—suggests that an already available blood test could estimate when Alzheimer's symptoms may begin within a margin of several years. The test detects a protein called p-tau217 found in blood plasma and the researchers incorporated the findings from that blood test into a statistical model to come up with the symptom timeline predictions.

Arthritis affects almost 60 million Americans, with about 1 in 5 US adults developing this type of joint pain as they age.

Caucasians are at the greatest risk of developing macular degeneration

A 2016 analysis across ethnic groups found, among other things, that white participants had the highest incidence of the disease, followed by Chinese, Hispanic, and Black participants. This study did not answer why that may be the case.

Memory disorders disrupt the brain's ability to make, store, or recall memories

These disorders stem from reversible issues like vitamin deficiencies or irreversible causes such as stroke or dementia. Only one type of dementia—familial Alzheimer’s disease—is directly inherited and accounts for about 20% of Alzheimer’s cases.

MS risk is shaped by geography, not just genes

Latitude—and related vitamin D exposure—seems to affect MS risk. People who migrate from a high-risk MS latitude (like northern Europe or the northern US) to a lower-risk latitude (like tropical areas) before age 15 tend to adopt the lower risk of their new country—suggesting there's a critical window for environmental exposure.

Poverty rates by US state

As of 2022, 37.9 million people in the US were living in poverty. But those people aren't evenly distributed among the 50 states. Some states and regions of the country are more impoverished than others. For instance, US poverty rates are relatively higher in the South than they are in the North. See the state-by-state breakdown with this map.

US depression rates at historic high among adults

More than 18% of US adults reported that they currently have or are being treated for depression in both 2024 and 2025. In the 2025 survey, more than 11,000 adults were surveyed. The numbers have ticked upward since 2015—by about 8 percentage points—with most of the increase occurring from the 2020 pandemic onward.

Learn the differences between mild cognitive impairment and age-associated memory loss

Mild cognitive impairment is a condition in which people experience more thinking and memory problems than expected for their age. It's often associated with depression and anxiety. Daily routines, writing things down, and healthy lifestyle choices can help cope with the condition, but there's no cure. The condition elevates the risk of developing dementia and Alzheimer's.

Mapping hearing loss in the US

Nearly 10% of Americans suffer from some degree of hearing loss, measured as the inability to hear sounds lower than 25 decibels. The incidence of hearing loss increases with age and is typically higher among men. Recent analysis produced a puzzling observation researchers can't quite explain: There's a larger incidence of hearing loss among rural populations than in urban centers. Explore the data with this map and explainer.

An Alzheimer's patient discusses her condition with children

Alzheimer's is a deadly disease that profoundly changes a person's abilities and personality, which makes it difficult to explain to kids. Responding to potentially uncomfortable questions with honesty (and relatable imagery) about the costs and nature of the disease goes a long way in fostering understanding.

In 2023, Native Americans had the lowest life expectancy at birth among all racial and ethnic groups

Native Americans and Alaska Natives face significant health disparities linked to chronic underinvestment in reservation health infrastructure, poverty, and multigenerational psychological harm—often called historical or inherited trauma.

Winter-risk SAD is more likely in regions above 40 degrees latitude north

Using latitude, depression prevalence, and populations of women and those aged 18-30, this map shows the risk of experiencing seasonal affective disorder during the winter. Researchers weighted latitude most (50%) and demographics least (5% each for women and young adults). Overall risk is not a useful predictor of prognosis for an individual.

Risk factors linked with ASD include older parents, preterm births, and toxic prenatal exposures

Though researchers agree that there is a strong genetic component to ASD development, certain environmental factors heighten that risk, with studies suggesting older parents, premature birth, maternal obesity, and air pollution exposure in utero all elevate risks of ASD development. There is no connection between receiving vaccines and ASD development.

Visualizing obesity rates across the US

Nearly 70% of adults in the US are either overweight or obese, rates that have tripled over the last 60 years. Severe cases have risen tenfold during this period. Factors like location, income level, and demographics contribute to various obesity levels across the US. Visualize the statistics with this article and chart series.

Super-agers: seniors 80 and above with the memory ability of people in their 50s

Studies show the number one indicator of whether someone is a "super-ager" is not diet or genetics, but the extent of their social relationships. Moreover, scans reveal noticeable physical differences in certain parts of the brain in patients with extensive social networks.

Smell is a robust memory cue for individuals with Alzheimer's disease

Odor is more effective than both visual and verbal cues for triggering autobiographical recall in Alzheimer's disease, according to 2021 research.

How reading and writing can lower dementia risk by almost 40%

Research published in 2026 that tracked almost 2,000 older adults for an average of nearly eight years suggests that lifelong exposure to intellectual stimulation, such as learning a language, reading, and writing, can lower dementia risk by as much as 40%.

Read the original 1907 paper on the first known Alzheimer's patient, which was identified by Dr. Alois Alzheimer.

An analysis of ancient texts found that dementia was rare in ancient Greece.

Recent evidence raises the question of whether conventional wisdom about amyloid plaques and their connection to Alzheimer's is wrong.

See the incidence of Lyme disease across all 50 states in 2023

The US states with the highest rate of Lyme disease—meaning cases per 100,000 people—were Rhode Island, Vermont, and Maine, in 2023. Rhode Island had 260 cases per 100,000 people, based on cases reported to the US Centers for Disease Control and Prevention. (Some users may encounter a paywall.)

More than 200 drug trials for Alzheimer's have failed or been abandoned since 2010, but two anti-amyloid infusion medications have netted FDA approval in recent years.

Nearly 1 in 4 Americans over age 65 is still working

While many of these Americans are often working part-time, the share varies significantly by US state. While roughly 29% of those over the age of 65 work in Vermont, only about 17% do the same in West Virginia.

A stroke occurs when blood flow to part of the brain is suddenly interrupted, either by a blockage (ischemic stroke) or bleeding when a blood vessel in the brain breaks and bleeds (hemorrhagic stroke).

Taxi and ambulance drivers appear to have the lowest risk of dying from Alzheimer's disease out of 443 occupations, which suggests that constant real-time navigation work strengthens the hippocampus and may help protect against the disease.