Girls, see if this sounds familiar. You look in a mirror one morning and notice you're taller -- and rounder. Through your nightgown, you see your breasts are bigger. You don't remember looking like that a few weeks ago! Over the next few weeks, you start noticing hair in places you've never had hair before. You've heard girls at school talk about getting their periods, and you wonder if that will happen to you soon. You feel ultraconfident, and then super sensitive -- all in the same day. What in the world is going on? Welcome to puberty.
Technically speaking, puberty is nature's way of transforming a child into an adult, all for the sake of reproduction. While both girls and boys go through puberty, girls reach puberty and sexual maturity at earlier ages than boys do.
Puberty isn't easy -- especially when you go through it before any of your friends.
"It's a huge amount of change in a very short period of time," says Pamela Murray, MD, MPH. "Change is always tough." Murray is a pediatrics professor at West Virginia University.
Your body is going to go through a lot in just one to two years:
Growth spurt: Before you start your period, you can grow up to 4 inches in just one year.
New curves: You'll gain weight, especially in your hips,...
So what's causing all of these changes? Hormones! Actually, the female hormone estrogen is the main one that's triggering all the changes in your body. Let's look at some of the changes girls can expect at puberty.
Increase in Height and Weight
Starting at around age 9, girls begin to gain about 17% to 18% of their adult height. If someone has commented that you are "all hands and feet," it's true! Your limbs grow first, then your trunk. Most girls grow fastest about six months before they start their first period (menarche).
You'll probably gain weight in puberty -- most girls do. You may notice more body fat along the upper arms, thighs, and upper back. Your hips will grow rounder and wider; your waist will become narrower.