The following excerpt is from the book The Ultimate Girls: Body Book Not-So-Silly Questions About Your Body:
How often do you or your friends use the word puberty? Probably not at all. But all of the physical and emotional changes that you’re going through are part of an ongoing conversation for most girls during the tween and teen years. Since we are doctors — and we like medically reliable terms — we’ll go with puberty.
Here’s our definition: puberty is the process that develops and changes your body physically from a girl to a woman. Here’s your definition: “Wow, what’s up with my body? A lot of stuff is going on!”
During puberty, your body will grow faster than at any other time in your life — well, except for when you were in your mother’s womb and when you were a tiny baby. You will grow taller, you will develop hair in new places, your private parts will change, and your breasts will grow. Surely you’ve heard about girls getting their periods. Maybe you’re wondering about your first period. What in the world is going on with that? You’ll also experience a roller coaster of new feelings and emotions. You can feel super confident one moment and ultrasensitive the next. In the morning, you may have it all together, only to fall apart in a single second by the first bite of your lunch. You’ll have to deal with mean girls, bullying, and attraction to boys. Not to mention TV shows, movies, the Internet, videos, and video games bombarding virtually every thought you have.
We’ll talk about all those things, but first let’s discuss puberty, which involves three main events: the growth of your breasts, the growth of pubic hair, and your first menstrual period. Typically, the changes unfold in exactly that order and can take anywhere from two to five years. Although these changes may seem weird or even scary, they are normal, healthy, and God-designed. Girls go through puberty at different ages and at different rates. It usually starts between the ages of eight and twelve.
Over the last few decades, more girls have begun puberty before the age of eight — even down to age six or seven. And your ethnicity can make a huge difference. If puberty starts before you’re eight years old (or has not started by the time you turn twelve), you should see your doctor just to be sure everything’s all right. So what kicks off the process? Hormones do. A gland is a part of your body that makes the chemicals called hormones. The bloodstream then carries the hormones to another part of the body (like from your brain to your breasts).
Puberty begins when your brain releases a bunch of these chemicals. The hormones called estrogen (made primarily in your ovaries) and human growth hormone (HGH, made in your brain) cause most of the changes in your body during puberty. Get ready for some drama!
When these hormones reach the muscles and bones, your body’s growth speeds up. If someone tells you, “You’re all hands and feet,” in a way they’re right. During puberty, your extremities grow first, then your trunk (back, chest, and abdomen). Most girls grow fastest about six months before their first period (which is called menarche, but more on that later).
You’ll grow taller during puberty. You’ll gain weight in different places. You’ll develop awe-inspiring superpowers — okay, just kidding about that last one. Most girls will notice more body fat along the upper arms, thighs, and upper back. Your hips may grow rounder and wider, while your waist can narrow. This is all totally normal and divinely designed (that’s always nice to know). For most girls, breast growth is the first sign of puberty; estrogen causes it. Some girls will first notice hair growing in their pubic area, while a few others first notice hair growing on their arms, legs, and armpits (axillae). Menstrual periods usually don’t come until later, typically when you’re twelve or thirteen. We know these changes can seem scary and strange to you and to other girls who go through them.
But don’t worry! As you learn more about what’s happening, it will make sense and you’ll feel better. Trust us. So let’s begin to address the many questions that are swirling around in your mind about these amazing, God-designed changes.
“Before I formed you in the womb I knew you, before you were born I set you apart.” –Jeremiah 1:5 “Your Redeemer…formed you in the womb.” –Isaiah 44:24