Where hair comes from
Every hair grows out of a tiny pocket in your skin called a follicle (FOL-ih-kul). Your follicles were all made before you were born.
At the bottom of each follicle is a living root. It makes new cells that stick together and push up, forming the hair.
The part of the hair you can see is called the shaft. It's made of keratin (KER-uh-tin), the same tough stuff as your nails.
Hair grows almost everywhere on your skin, except a few spots like your palms, the soles of your feet and your lips. A lot of it is so fine and light you barely notice it.
Why a haircut doesn't hurt
The hair you can see is dead. It has no nerves and no blood, so a haircut doesn't hurt at all.
The root under your skin is alive, and it's wrapped in nerve endings. That's why a pulled hair says ouch, but a snipped hair says nothing.
Your hair still feels things, though. When something brushes a hair, it wiggles the root, and the nerves around the root notice.
Growing, resting and falling out
You have about 100,000 hairs on your head. Head hair grows about half an inch a month.
Each hair grows for a few years, then rests, then falls out. Then a new hair starts growing in the same follicle.
So it's normal to lose about 50 to 100 hairs every day. You don't notice, because new ones keep coming in.
Eyelashes and eyebrows only grow for a few months before they rest and fall out. That's why they stay short.
Colors and curls
Hair color comes from melanin, the same coloring that's in your skin. Lots of the brown-black kind makes dark hair. More of the red-yellow kind makes red hair. A smaller amount makes blond hair.
As people get older, their hair roots make less melanin. Then new hairs grow in gray or white.
Whether hair is straight, wavy, curly or coily depends partly on the shape of the follicle. Round follicles tend to grow straighter hair. Flatter, curved follicles tend to grow curlier hair.
Every kind of hair is beautiful, and each kind likes its own kind of care.
Eyebrows, eyelashes and more
Eyebrows help keep sweat and rain from running down into your eyes.
Eyelashes are like little brooms. They catch dust, and if something touches them, your eyes blink fast to stay safe.
Hairs inside your nose catch dust and germs before they get to your lungs.
The tiny hairs on your arms and legs help you feel things brushing past, like a bug landing or a breeze.