Health
Discover facts about health. Small discoveries that change the way you see familiar things.
Health
Period cramps come from a muscle doing real work: the uterus contracts to shed its lining.
Period cramps come from a muscle doing real work: the uterus contracts to shed its lining. Hormone-like chemicals called prostaglandins help drive those…
Discover more
Your body runs on just a few grams of iron.
Your body runs on just a few grams of iron. An adult typically contains about 3–4 grams of iron, much of it held inside hemoglobin in red blood cells. There…
Discover more
Vocal cords are surprisingly small bands of muscle tissue, measuring less than an inch long in most adults, yet they can vibrate up to a thousand times per second to produce high-pitched sounds.
Vocal cords are surprisingly small bands of muscle tissue, measuring less than an inch long in most adults, yet they can vibrate up to a thousand times per…
Discover more
One gene links earwax texture with underarm odor.
One gene links earwax texture with underarm odor. A variant of ABCC11 is associated with dry earwax and reduced production of compounds that skin bacteria…
Discover more
A mother can carry cells from her child for decades after pregnancy.
A mother can carry cells from her child for decades after pregnancy. Some fetal cells cross the placenta and settle in maternal tissues, creating a tiny…
Discover more
A hot drink can increase cooling—if the extra sweat evaporates.
A hot drink can increase cooling—if the extra sweat evaporates. In a small exercise study, warm water triggered enough additional sweating to offset the heat…
Discover more
STACKY FOR IPHONEA bigger world.
One discovery
at a time.
Keep discovering with Stacky. Interesting facts in an app that is always within reach.
A persistent craving for ice can be a clue to iron deficiency.
A persistent craving for ice can be a clue to iron deficiency. Pagophagia—the compulsion to chew ice—is associated with iron deficiency, even without anemia.…
Discover more
Anger and heavy exertion can stack their demands on the heart.
Anger and heavy exertion can stack their demands on the heart. An international study of people who had suffered a first heart attack found that exertion and…
Discover more
A missed coffee can produce real withdrawal.
A missed coffee can produce real withdrawal. With regular caffeine use, the body adapts to a stimulant that blocks adenosine, a chemical involved in…
Discover more
A cheese-industry dream study became a bedtime legend.
A cheese-industry dream study became a bedtime legend. In 2005, the British Cheese Board reported that volunteers eating different cheeses described different…
Discover more
Emotional tears carry more than salt water.
Emotional tears carry more than salt water. Emotional and reflex tears can differ in protein content and other constituents. Crying also involves changes in…
Discover more
A tired muscle can cramp without a simple electrolyte shortage.
A tired muscle can cramp without a simple electrolyte shortage. Exercise-associated cramps can involve changes in the nerve signals that excite and inhibit…
Discover more
A large experiment found that making a smile can shift reported happiness.
A large experiment found that making a smile can shift reported happiness. The Many Smiles Collaboration tested participants across 19 countries. Deliberately…
Discover more
The muscles moving your fingers are elsewhere.
The muscles moving your fingers are elsewhere. Tendons carry force from muscles in the hand and forearm to the finger bones, like cables pulling a joint. That…
Discover more
Soap gets germs off your hands without needing to kill every one.
Soap gets germs off your hands without needing to kill every one. Soap helps loosen oily dirt and microbes from skin so running water can carry them away.…
Discover more
Keratin proteins structurally weave together so tightly that a single strand of healthy human hair can support roughly three ounces of weight, meaning a full head of hair…
Keratin proteins structurally weave together so tightly that a single strand of healthy human hair can support roughly three ounces of weight, meaning a full…
Discover more
Those drifting specks in your vision are often shadows inside your eye.
Those drifting specks in your vision are often shadows inside your eye. Tiny strands clumping in the vitreous—the gel filling the eye—can cast shadows on the…
Discover more
A coffee nap tries to line up two different clocks.
A coffee nap tries to line up two different clocks. A short nap can reduce sleepiness while caffeine is being absorbed. Researchers tested the combination in…
Discover more
Muscle memory may leave traces beyond the muscle you can see.
Muscle memory may leave traces beyond the muscle you can see. Training changes muscle fibers and the systems that control them. Researchers have investigated…
Discover more
Your fingernails grow roughly twice as fast as your toenails.
Your fingernails grow roughly twice as fast as your toenails. A study of young adults measured averages of about 3.5 millimeters a month for fingernails and…
Discover more
You hear a version of your voice nobody else gets.
You hear a version of your voice nobody else gets. While you speak, sound reaches your ears through the air and through vibrations carried by your head. Those…
Discover more
Your gut bacteria turn part of dinner into gas.
Your gut bacteria turn part of dinner into gas. Carbohydrates that escape digestion in the small intestine reach microbes farther along the gut. As those…
Discover more
CPR's rhythm is fast enough to pump, slow enough to refill.
CPR's rhythm is fast enough to pump, slow enough to refill. Adult chest compressions are recommended at 100 to 120 per minute, with full recoil between…
Discover more
Morning erections can be the visible end of something that happened repeatedly during sleep.
Morning erections can be the visible end of something that happened repeatedly during sleep. Changes in nerve activity, especially during REM sleep, can…
Discover more