Health
Discover facts about health. Small discoveries that change the way you see familiar things.
Health
Total body water percentage drops as you get older
The percentage drops because water is not distributed evenly across body tissues. Infants have a larger share of water-rich tissue, while older adults…
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Why people float more easily in salt water
Salt dissolved in water makes it denser, so a given volume of salt water pushes upward more strongly than the same volume of fresh water. That extra buoyant…
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Why pool water can turn blonde hair green
Copper can build up on hair after contact with pool water or hard water. Because blonde hair offers little color to hide the deposit, it can take on a green…
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The hidden part of your nail that controls its shape
The nail matrix, tucked under the cuticle, is the living growth zone that makes new nail. Because it builds the nail from its base, damage there can leave a…
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Urine consists almost entirely of water and useless urea
As the kidneys filter blood, they direct urea and other waste into urine, which is mostly water. The water is the delivery vehicle; the urea is cargo the body…
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Essential fat physically cushions your fragile organs
Fat beneath and around organs helps cushion them as your body moves, softening some everyday bumps and shifts. It’s not just stored fuel: a minimum amount…
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Cartilage carries its own remarkably slippery surface
Joint cartilage combines a water-rich structure with lubrication at the contact surface. Fluid helps carry load and reduces how strongly the solid surfaces…
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Human hair slowly grows roughly six inches per year
About half an inch of hair appears each month because cells at the root keep dividing and pushing the strand outward. The visible hair is already formed…
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Frostbite can destroy cells with ice crystals
As tissue freezes, ice crystals form in the fluid between cells and can damage their delicate membranes.
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A tourniquet buys time for emergency care—not a safe countdown
It controls life-threatening limb bleeding by compressing blood vessels, which also limits circulation beyond the band. Emergency guidance stresses recording…
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Vocal tract functions perfectly as a physical acoustic tube
Your vocal folds start the sound, but the tube above them gives it much of its character. Moving your tongue changes the tube’s shape and the resonances it…
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Freezing cold air physically shrinks the respiratory airway
In reactive airways, cold air can make the muscles around the breathing tubes tighten. The narrowed passage leaves less room for air, which can make breathing…
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A classroom assistant's scream reached a recorded 129 decibels
Guinness records Jill Drake's performance at London's Millennium Dome in 2000. It is an exceptional measured event, not the expected volume of everyone's…
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Why a fast ascent can make nitrogen bubble inside you
Under high pressure, nitrogen dissolves into the body. A rapid ascent drops the pressure around it, and the nitrogen can gather into bubbles—much like gas…
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Fine hair and fewer hairs are different things
A large international study found lighter hair tones associated with smaller strand diameters, but not a clear change in overall hair density. A head of fine…
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Your body makes water while burning fuel
As cells use carbohydrates and fats for energy, the chemical reactions leave water among their byproducts. That means your body makes a little water even…
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Human cheeks contain highly specialized buccal fat pads
The buccal fat pads are cushions tucked between cheek muscles and facial tissues. They let those layers slide past one another as you chew; removing some can…
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A whisper can make a sore voice work harder
In a study of patients with voice complaints, many squeezed the structures above their vocal folds more during whispering than during ordinary speech. A…
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Medical codes distinguish an alligator bite from a crocodile bite
U.S. ICD-10-CM gives them separate entries: W58.01 for an alligator bite and W58.11 for a crocodile bite, with additional characters specifying the encounter.…
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Progesterone spikes dramatically right after ovulation ends
After ovulation, the emptied follicle in the ovary produces progesterone, which helps prepare the uterine lining for a possible pregnancy. The body stages…
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Cherry pits contain a poison that appears when crushed
Amygdalin is sealed inside the hard cherry pit. If you crush or chew the pit, that barrier breaks and the compound can release hydrogen cyanide; an intact pit…
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Some hospitals charged parents to hold their baby
Some hospitals have listed skin-to-skin contact as a billed service, charging parents to hold their newborn immediately after birth.
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Your body makes formaldehyde every day
As your cells process nutrients and build or break down molecules, they naturally produce tiny amounts of formaldehyde. The same chemical has a lab-preserving…
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Medical billing has a code for being struck by a duck
ICD-10-CM includes W61.62 for being struck by a duck, with extra characters specifying the encounter. W61.62XD denotes a subsequent encounter, such as…
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