Low cell division rates in heart cells make heart cancer particularly rare

About 40% of cancer cases are linked to preventable risk factors

Maintaining a healthy weight, engaging in regular physical activity, and consuming a balanced diet can lower cancer risk. Research indicates that about 40% of US cancer cases are linked to preventable factors, including poor diet and inactivity. Understanding these mechanisms empowers individuals to adopt healthier lifestyles for cancer prevention.

Large animals like giraffes and elephants have evolved unique cancer defenses

One may expect the larger an animal is, the more likely it is to develop cancer—simply because there are more cells and more chances for a dangerous mutation. However, some large animals show cancer rates almost 10 times lower than humans—a phenomenon known as Peto's Paradox.

The immune system is in a constant fight against mutations

At the heart of cancerous cells is the development of mutations—an ongoing and continuous process that happens frequently. So why don’t we get cancer immediately? The body’s immune system has developed intricate methods to detect and destroy cancer cells, catching the vast majority before they get the chance to evolve into tumors.

Chemotherapy slows cancer by interfering with cell division

Cancer cells divide much more frequently than most normal cells. Most chemotherapy drugs are designed to interfere with cell division, thereby targeting harmful cells while attempting to leave healthy cells alone.

Breast, prostate, and lung cancer are the most common forms of the disease

Close to 1.8 million cases of cancer are diagnosed each year in the US, with more than 600,000 deaths (about 0.2% of the total population). This visualization tool offers a searchable database of aggregate statistics on common cancers by gender, race, state, and other demographic information.

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

Heart attacks are less harmful at night

When heart attacks occur during the day they typically do more harm to the heart tissue than if they occur at night. A 2025 study suggests that daytime heart attacks have higher levels of immune cells called neutrophils to contend with and they appear to worsen the injury. Scientists confirmed this same pattern in experiments with mice. (Some readers may experience a paywall.)

How does cancer spread through the body?

Cancer usually begins with one tumor, but it can spread to other organs if not removed. This video breaks down how cancer moves to these new areas and why some organs are more likely to get infected than others.

Cells can last in the human body from days to a person's entire life

Despite claims that a person's body replaces itself every seven to 10 years, the rate at which cells die and are replaced varies by cell type. Gastrointestinal cells that line the digestive tract and stomach last only a few days, while some heart muscle cells and most neurons are around from birth until death.

Roughly 1 in every 4,300 individuals in the US has mitochondrial disease

Roughly 1,000 to 4,000 kids are born with these conditions each year in the US though many of the diseases are fatal. Mitochondrial disorders often affect the organs that require the most energy, including the heart, brain, and muscles.

What does a beating human heart look like?

Tucked behind your rib cage and between your lungs sits your heart. This knot of cardiac muscle will (typically) beat billions of times throughout your lifetime, sending oxygenated and nutrient-rich blood throughout the body, powering countless biological processes that have enabled you to read this very paragraph. This two-minute video provides a glimpse of the mechanics happening inside your chest via an animated anatomical model.

Explore the abundance of different types of cells in the human body

Lacking a nucleus and other organelles to maximize space for oxygen-carrying hemoglobin and enhance maneuverability through narrow capillaries, there are about four times as many red blood cells and platelets as all other cell types in the body combined. However, about half of the body's cell biomass consists of skeletal myocytes, or muscle fibers.

There are hundreds of subtypes of cancer, making a universal cure nearly impossible

Cancer is an umbrella term for over 200 different diseases, each with its own subtypes, genetic mutations, and behaviors. This diversity means that a treatment effective for one cancer type or patient may be ineffective for others. Moreover, as tumors grow, their cells accumulate different mutations, creating subclones with unique characteristics.

Yes, you can die from a broken heart

Researchers reviewed the health records of about 200,000 people diagnosed with broken heart syndrome from 2016 to 2020 and the death rate was 6.5%—with men's deaths roughly doubling that of women.

Explore the gap in what Americans die from versus news coverage on death causes

Top killers like heart disease, stroke, and liver disease, though they represent a significant burden nationally, are not often extensively covered in the media.

Protecting astronauts against space radiation

Outside the protective atmosphere of Earth, astronauts are constantly bombarded by radiation, which, among other dangers, increases the risk cancer. While those of us on Earth can mitigate the effects of similar radiation by limiting exposure,...

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

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.

'Buffy coats': The 1% of blood that helps fight off disease

When blood is centrifuged, white blood cells and platelets form a layer called the buffy coat between the plasma and red blood cells. This layer makes up less than 1% of blood, but its heightened leukocyte concentration makes it useful for toxicology research.

Trials ongoing for a 99% accurate, AI-powered blood test

The UK's National Health Service has launched a trial for a blood test that can detect a dozen types of cancers with just ten drops of blood. An AI tool looks for genetic material known to be released by tumors, allowing for cancer detection before tumors are large enough to be imaged.

Donated hearts remain viable three times longer now with new tech

Advances in organ perfusion systems have significantly lengthened the amount of time donated hearts can remain viable for transplant, expanding the possibilities for donor organs to wider geographic areas. "Heart in a box" devices, developed in recent years, enable effective oxygen flow in the donor heart during transport, which means that hearts can now travel farther to potential recipients and still be in good condition.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

What conditions can be treated with stem cells?

Stem cell research is a global enterprise, and much of the work is being done in Europe. This page gives readers a good sense of the medical conditions stem cell researchers in Europe focus on, and the specific research challenges they address. This page also offers links to in-depth information about many of the research projects.

The Lazarus Effect is when a heart begins beating on its own after declared death

Formally called autoresuscitation, this rare phenomenon occurs when someone is declared dead following a cardiac arrest but their heart beats again without help—making it seem like the person came back to life. Doctors don't know the exact cause.

Less than 1% of aging studies consider menopause and its effects

Nearly all studies researching the biology of aging don't consider menopause in their setup, in part because menopause is difficult to emulate in animal models. Menopause is uncommon in the animal world beyond humans and whales. This presents a problem for medicine and science because about 75% of aging-related diseases are likely influenced by menopause.

Watch an expert's take on the rare disease hantavirus—and why it's not of great concern to the general population

This rare zoonotic disease, transmitted to humans primarily through infected rodent droppings, urine, or saliva, is rarely spread between people. The disease was of particular concern in spring 2026, when an outbreak occurred on a 150-person cruise ship, prompting a flurry of action, including contact tracing for passengers in their home countries. The disease can be fatal. But early care—primarily oxygen support—can help patients survive.

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.

Microplastics are infiltrating the human body with unclear but concerning effects

Scientists have linked microplastics to immune system damage, hormone disruption, inflammatory diseases, and even cancer—yet most of their health impacts remain unknown due to limited research. Studies suggest we ingest about a credit card's worth of plastic weekly.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

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.

Tattoos remain visible on your skin thanks to immune cells called macrophages

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

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

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

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

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

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

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.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.