Why vascular dementia develops

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.

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.

1440: Everything you need to know about Alzheimer's

What is Alzheimer's, and is it different from dementia? In short, yes—Alzheimer's is a specific brain disease that falls under the umbrella of dementia. However it is the most prevalent form of the condition, accounting for 60 to 80% of reported dementia cases.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

How neurodegeneration happens, the underlying disease process of dementia

Dementia symptoms may vary between individuals, and may include mood changes, difficulty walking, speaking, and memory problems. It can progress over many years, occurring due to progressive damage to nerve cells in the brain. This degradation may happen for myriad reasons, and its triggers are under investigation.

Visualizing a stroke at the microscopic level

By far the most common type of stroke is what is known as an ischemic stroke. This occurs due to either an embolus (a blood clot that travels to the brain from elsewhere in the body) or a thrombus (a blockage that forms within the brain itself).

What is the blood brain barrier?

Every blood vessel is lined with endothelial cells that act as filters between blood and the rest of the body. In the brain, these cells are tightly packed together to keep a close watch on what substances can access the vital organ. This protective measure poses an obstacle to drugmakers looking to deliver drugs to the well-defended brain for conditions like Alzheimer's. Watch a quick overview here.

What is cardiovascular disease?

Cardiovascular diseases are a range of related health conditions that develop in the heart and blood vessels. This article and related infographics detail cardiovascular disease types and treatments.

How do 'dementia villages' work?

The goal of good dementia care is to preserve a patient's quality of life as the incurable disease progresses, maximizing their ability to lead normal lives and maintain their health and dignity. Dementia villages are small neighborhoods built for people with severe dementia, with typical neighborhood haunts like salons or grocery stores staffed by people trained in dementia care, helping residents maintain a sense of autonomy and connection.

Wet macular degeneration affects 10%-15% of those with macular degeneration

This form of molecular degeneration refers to when excess blood vessels form in the back of the eye and damage the macula. If someone with this condition looks at straight lines, they will typically appear wavy or crooked.

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%.

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

The brain has three main parts—the cerebrum, brain stem, and cerebellum—each combining to control the entirety of the body's operations. Alzheimer's progressively deteriorates the circuitry in these structures, resulting in what we see as the symptoms of the disease.

Some dementia cases may be linked to microorganisms in the brain

Researchers now know that, much like the gut, the brain is home to an ecosystem of microorganisms—the brain microbiome. While this area of study is still new, some scientists believe 50% of bacteria-caused dementia cases could be treated. (Some users may encounter a paywall.)

Repeated head injuries can lead to CTE and early dementia

Chronic traumatic encephalopathy is a progressive neurodegenerative disease caused by repeated trauma to the head. The condition has become a particular concern in sports like football and soccer, from youth to professional leagues, where repeated low-level concussive events are likely.

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.

Brain death is a uniquely modern problem stemming from modern ventilators

Patients who would have once died from devastating brain injury can now live on a ventilator for a long period of time, creating ethical, medical, and legal dilemmas.

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.

See how the Ebola virus affects blood circulation in the human body

Ebola infects and disables immune cells, causing a cascade of events that result in small blood clots throughout the body, weakening blood vessels, and interrupting blood flow to key organs.

Central vestibular disease is another common cause of vertigo

Unlike peripheral vestibular disease that is caused by factors like inflammation in the inner ear, central vestibular disease involves dysfunction of one or more parts of the central nervous system. Vertigo of this type may last for seconds, hours, or even days. It's typically caused by issues with the brain stem and cerebellum and could be caused by stroke, tumor, and vestibular migraine, among other conditions.

Untreated malaria can lead to blocked blood vessels in the brain, coma, and organ failure

Malaria is treatable with medications, but sometimes even after treatment, infection can come back because the disease-causing parasite wasn't completely eliminated. Patients may also have symptoms that emerge years after the initial infection and treatment.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Arteries with microplastic deposits linked to higher risk of cardiovascular events

Research shows that microplastics and nanoplastics can accumulate in major arteries, and patients with these deposits are significantly more likely to suffer heart attacks, strokes, or death. These deposits are possible due to these particles' ability to cross blood barriers.

Exercise improves brain blood flow, stimulates neural growth, and more

Exercise has dramatic effects on human biology, including reducing some of the long-term harms associated with chronic stress. Its effects are also pronounced in the brain, including improved memory retention, sleep, cognitive functioning, and more.

Historians theorize Vincent Van Gogh suffered from Ménière's disease or epilepsy

A century after researchers suggested he suffered from epilepsy, some researchers in the 1990s began to support an alternate diagnosis: Ménière's disease, since he had suffered from severe, repeated attacks of disabling vertigo. Still, some researchers remain skeptical of the Ménière's diagnosis. One posits that Van Gogh had temporal epilepsy complicated by his absinthe consumption.

Scleroderma, which causes skin to harden and scar, has no FDA-approved treatment

It's an autoimmune disease that disproportionately causes worse complications in African American people for unknown reasons. It causes the body to overproduce collagen after the immune system attacks the body's own connective tissue, leading to excess collagen deposits and restricted blood circulation as small blood vessels are damaged. It can damage various organs, including the lungs.

Why hibernating bears don't get blood clots

For mammals, long periods of inactivity can lead to health problems—blood flow slows and pools, veins kink and distort, and clots potentially form. Hibernation takes this risk to the extreme, yet for decades why animals like bears did not exhibit...

Type 2 diabetes is a chronic disease that develops over time

Almost 90 to 95% of people with diabetes have Type 2 diabetes, occuring when the pancreas doesn't make enough insulin or the insulin fails to work correctly. Insulin malfunction causes the pancreas to crank out increasingly high amounts of the blood sugar-regulating hormone, leading to overwork and reductions in production.

This real-time tracking of the hantavirus cruise ship outbreak in May 2026 offers a unique glimpse into the global reach of the outbreak and whether the virus sickened passengers and their communities around the world.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Poison ivy's rash-causing compound is found in the plant's roots, stem, and leaves—so coming into contact with any part of the plant can lead to rashes for the 85% of people who are allergic to it.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Roughly 43 million US borrowers owe roughly $1.7T in student debt, the second-largest source of consumer debt behind mortgages.

Art theft is the third-largest source of criminal revenues worldwide, thanks in part to the subjective nature of valuing a work of art.

The 1987 Nintendo video game 'Stadium Events' isn't known for being particularly fun, but its scarcity has made it a highly sought-after item that has sold for up to $35K at auction.