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

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

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

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.

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.

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.

Why vascular dementia develops

This type of dementia, the second most common form after Alzheimer's, develops due to microscopic bleeds and blood vessel blockages in the brain. The condition isn't curable but medications to help with blood clotting and high blood pressure are part of a suite of interventions designed to minimize damage to the brain.

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

Neurodegeneration is the process underlying dementia, but it may happen for myriad reasons, and its triggers are under investigation.

Untreated hearing loss is linked with dementia risk

Hearing loss does not cause dementia, but it does increase the risk of developing dementia and research suggests that people who wear hearing aids for age-related hearing loss also maintain better brain function than those who don't.

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.

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.

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.

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%.

Dementia describes progressive memory issues that impact daily activities

Although Alzheimer's disease is sometimes thought of synonymously with dementia, there are multiple types of dementia, which manifest in memory loss and other symptoms that make it challenging to perform daily tasks. These types include Lewy Body dementia, vascular dementia, and frontotemporal dementia. Parkinson's disease is not a form of dementia, but this movement disorder can sometimes develop into issues with memory and a formal diagnosis of dementia.

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

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

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.

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.

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

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

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.

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.

Sitting 10+ hours per day increases dementia risk

People who sit for at least 10 hours per day are more likely to develop dementia, according to a study published in 2023. This article details the study on the murky relationship between brain health and prolonged sitting. This study involved...

Some dementia cases may be linked to treatable microorganism infections in the brain.

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.

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

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.

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.

Alzheimer's as a family disease: When children become "parents"

Kitty Eisele's 81-year-old dad went missing while on a snowy, four-hour drive from Minneapolis to Iowa City. It was the first emergency that spelled out the danger of her dad's dementia diagnosis—and captures how Alzheimer's impacts entire families, with the influx of responsibility that comes with caregiving.

Brain training game creates long-lasting changes in the brain that may help protect against dementia.

Some data links schizophrenia to older paternal age and birth complications

Yet both associations are not yet considered firm enough to definitively be causative. Schizophrenia is a multi-causal syndrome and a mixture of factors, including genetics, are widely believed to be behind its development.

How aging degrades neural functioning in the brain over time

Aging affects the brain perhaps more than any other organ in the body. Throughout life, the brain experiences radical shifts in the number of neurons, synaptic connections between neurons, and hormone levels that regulate our mood and processing.

Can your identity be preserved amid dementia?

Memory loss associated with progressive dementia raises questions about whether a person's identity can be maintained during the disease's progression. One outlook suggests we define ourselves by our social relationships—offering a potentially more humane approach to caring for those with dementia.

After a dementia diagnosis, it's important to plan ahead but also savor the moment

The next steps after a diagnosis include taking lifestyle steps to slow disease progression and completing legal paperwork about long-term medical preferences. It's also important to appreciate the moments and days ahead and find humor in them, when possible. (Some users may encounter a paywall.)

Aging is a complex biological process affecting our cells, tissues, and organs.

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

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.

MS Drugs reduce inflammation, helping reduce relapses and slow disease progression

Disease-Modifying Drugs calm the body's inflammatory response to help stave off relapses—when new or existing MS symptoms show up for a day or longer. Avoiding smoking, exercising, reducing stress via mindfulness, checking for vitamin D deficiencies, drinking more water and eating well, all can slow disease progression. [The jury's still out on if HRT around the time of menopause may reduce dementia risk](https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(25)00122-9/fulltext) Estrogen can reduce inflammation and support neural growth in the brain, and some research has suggested that beginning hormone replacement therapy around menopause—versus later in life—reduces Alzheimer's disease risk. Still, a recent systematic review concluded that taking HRT didn't affect dementia risk, regardless of when women started taking it, so the science remains unsettled.

Hearing loss is linked with brain volume reductions

The brain looks different as a result of hearing loss, with reductions in brain volume overall and in specific areas, and these changes are hypothesized to impact cognition. Exactly why hearing loss alters cognition is an active area of research, but theories include that the elevated cognitive load of straining to hear affects brain power available for thinking and memory and that hearing loss leads to social isolation which boosts dementia risk.

Resistance training is linked to better memory and cognitive function in older adults.

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.

How family members disappeared into dementia

This narrative feature describes one family's troubling experience with frontotemporal dementia, or FTD, which emerges in the prime of adult life — as young as 40, in some cases — and degrades the brain's ability to plan, organize, express language, understand social cues, and exercise judgment.

How Alzheimer's caregivers get pulled into their loved one's reality

Caregivers, most often children and spouses, do not just witness a family member's cognitive decline—they also often become drawn into it, navigating a world in which the typical rules of time, order, or logical continuity may not apply.

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.

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.

How Alzheimer's disease affected one family as symptoms progressed

News program 60 Minutes interviewed a couple navigating aging and Alzheimer's over a 10-year period to illustrate the effects of the disease on their lives.