Sickle cell trait can put people at elevated risk of heat-related illness

Exertional heatstroke is a top killer of athletes and soldiers-in-training

Often characterized by collapsing while exercising in the heat with intense sweating, this type of heatstroke among otherwise healthy people occurs when the body loses the ability to cool itself during intense exercise and the body's core temperature has risen to 104 degrees Fahrenheit or higher and cannot cool itself. If treated quickly, it's often survivable, though it can cause lasting damage.

Heat-related complications are of greater concern for distance runners than cardiac threats

Analysis of more than 130,000 runners in Tel Aviv events during a seven-year period indicated that the runners were 10 times more likely to experience heatstroke than serious cardiac problems. Scientists suggest that runners should take 10 to 14 days to acclimate to a hot climate before tackling a serious run.

Carrier screening enables individuals without symptoms to see if they carry a gene for disease

Some conditions are autosomal recessive—meaning a person may carry a gene for that condition, but not have symptoms. Cystic fibrosis, sickle cell disease, and Tay-Sachs disease are examples of autosomal recessive diseases in which a person must inherit two copies of a nonfunctioning gene—one from each parent—to develop disease.

More extreme heat days are putting human health at risk in both the short and long term

America is generally experiencing more frequent extreme heat days, over a longer period, in certain parts of the country. The heat-related death toll is rising, and beyond those direct deaths, extreme heat can also have troubling ripple effects including elevated violence and decreased productivity.

10 percent of SAD cases occur in the summer

Despite its significantly lower incidence, summer-risk SAD is as significant as its winter counterpart. Rather than being prompted by less light, the summer version is typically spurred by high temperatures, strong light, distinct summer time social pressures (appearing in a bathing suit, for example), and pollen. Common treatments include keeping cool and prioritizing sleep.

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.

Extreme weather conditions heighten cholera risks in settings like refugee camps

Runoff from sewage—exacerbated by situations like flooding or extreme rains—heightens this threat. Increasing temperatures also create the ideal conditions for the bacteria to reproduce, increasing transmission risks.

The first CRISPR-approved treatment was for sickle cell anemia in 2023

Victoria Gray was the first patient to receive a CRISPR-based therapy, which eliminated her symptoms and restored her health. The therapy's initial cost of $2.2M has kept it out of reach of many patients.

Swimming boosts the risk of contracting swimmer's ear by fivefold

The term swimmer's ear is a bit of a misnomer since other factors including scratches to your ear from Q tips, trapped perspiration inside the ear when you sweat, and living in tropical climates can elevate the risk of contracting this outer ear infection. But swimming poses the greatest risk: widely cited research has found that swimming elevates the risk of contracting this infection fivefold.

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.

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.

How did segregation in the US affect blood donations?

When the US established its first nationwide network of blood banks in 1941 with the hopes of restoring the dwindling reserves of military members, it was quick to emphasize blood donated by Black Americans wouldn't coat the veins of white servicemen. Historians say this policy was meant to appease white Southerners who believed Black blood was inferior to their own.This policy was leaked to the press that same year.

HSAs are frequently criticized for exacerbating inequality in healthcare access

Health savings accounts offer large tax advantages, but require personal contributions. Some argue that the tax advantages benefit wealthy individuals more than anyone else and that HSAs don't do much to help people who can't afford to regularly contribute to one. As a result, HSAs only decrease costs for those who can comfortably invest in them, and health inequalities between high-income and low-income individuals are exacerbated.

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.

Why do you shiver when cold?

Humans are warm-blooded creatures, so our bodies like to maintain internal temperatures separate from and typically above those in their environment. This is made possible by a process known as thermoregulation. When the brain's hypothalamus senses a drop in the body's core temperature, skeletal muscles may be ordered to shiver, sending out waves of muscle contractions and exothermic biochemical reactions whose byproduct includes heat and energy.

Two-thirds of soldier deaths during the war were due to disease

Roughly two-thirds of all Civil War deaths resulted from disease rather than battle. Poor sanitation, contaminated water, and limited medical knowledge made camps breeding grounds for dysentery, typhoid, and other deadly infections.

On average, people smell worse if they're sick

For a small 2014 research study, a panel was tasked with sniffing the smelly t-shirts of people who had been injected with a compound known to activate the immune system and those of controls without the shot. It found that those who were acting as if unwell (due to the injection) generally smelled worse. Subsequent work found that those who sniffed unpleasant odors had a mild immune response of their own—perhaps to protect them from disease. (Some users may experience a paywall.)

Healthy adults should perform 'progressive resistance training'

That's the recommendation in March 2026 from the American College of Sports Medicine. They reviewed existing studies on the topic and concluded that resistance training with progressively more weight and repetitions improves muscle strength, size, power, endurance, gait speed, balance, and more.

What is space sickness?

Mix motion sickness minus gravity with a host of other variables, and you’ve got a recipe for space adaptation syndrome. It can hit anyone, even astronauts who escaped the issue previously. This article details the history and science behind space sickness.

The 'kissing bug disease' occurs when a bug's parasite-laden poop gets into your blood

Chagas disease transmission can occur when triatomine bugs bite someone infected with a Trypanosoma cruzi parasite and then bite someone else, passing on the pathogen, though the parasite can also be transmitted in other ways, including via food, congenitally, and through blood transfusions. The bugs tend to feed at night and can bite anywhere on the body, but their reputation for biting people around the mouth and eyes created the idea that the bugs were "kissing" humans. Recent research suggests the disease may be endemic in the US.

Changes in vision or eye pain can be early MS symptoms

This occurs due to myelin degradation around the optic nerve, impairing its ability to transmit visual information to the brain. Individuals may especially experience eye symptoms after exercising or taking a hot shower because boosted body temperatures slow down nerve function in nerves already damaged by MS.

CTE is a major threat to NFL players

A week before Super Bowl LVII, Boston University released findings from a study diagnosing 91.7% of former NFL players in their 376-person study with chronic traumatic encephalopathy. It was a stark comparison to the less than 1% of CTE diagnosis in non-football players.

Children under 5 account for 76% of all malaria deaths in Africa

The main hypothesis for why the disease hits this age group the hardest is that children this young have still-developing immune systems. Pregnant women and people with HIV/AIDS are also at higher risk of severe infection.

Over time, people develop a resistance to spicy foods

TRPV1 is a receptor in the body that detects potentially harmful things and responds in a variety of ways, including sweating, tearing up or a runny nose. Over time, more exposure to spicy foods can build up a resistance that minimizes these reactions.

Pregnancy causes a woman's blood volume to increase by up to 50%

This change, to support the developing fetus, puts stress on the heart and blood vessels. A pregnant woman's heart rate also increases as she pumps more blood each minute to support fetal growth.

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.

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

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

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

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

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

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

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

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.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

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

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

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

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

The original copy of the Declaration of Independence is not a pristine document, and even features a smudged anonymous handprint in the bottom left corner.

View the ten deadliest tornadoes in US history.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by more than 1.5 million Muslims each year.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Dozens of S&P 500 stocks, including Coca-Cola and Walmart—known as the dividend aristocrats—have increased dividends every year for 25 years

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.