As you get older, your body will change — on the inside and the outside. This is part of growing up. It's called puberty. What Is Puberty? Puberty is when a person's body changes from a kid to an adult. Girls become women. Boys become men. The changes of puberty happen slowly. When things change, it can feel a little scary. Knowing what to expect can help you feel better. When you have questions, ask your mom, dad, doctor, or another trusted adult. How Will My Body Change on the Outside? Let's start from the top of your body and work our way down. The skin on your face will get oily and you may get pimples. Your breasts will start to grow. (Just like people come in many shapes and sizes, so do breasts. There's no one right size for breasts.) Hair will grow on body parts other than your head. It will grow under your arms, on your legs, and in your private area (around your vagina.) When you sweat, it will smell stinky — especially under your arms. You will get taller. These changes are normal and healthy. How Will My Body Change on the Inside? It might not seem like it, but a lot is happening on the inside too. The biggest thing that happens is that you will get your period (called menstruation). This is when blood comes out of your vagina, but you are not sick or hurt. When you get your period, you will see blood on your underwear, on toilet paper, or in the toilet bowl. Girls wear a special pad in their underwear to catch the blood. Periods usually happen once each month and last for 3 to 7 days. When you have your period you may feel cranky, tired, or sad. Some girls get stomachaches. If your stomach hurts or you're not feeling well, always tell your mom, dad, or school nurse. How Will I Feel? Puberty might cause strong emotions, like feeling angry. You may have other feelings too: You might feel happy one minute and sad the next. You might think another person is cute, and like them a lot. You might feel like touching yourself in your private area. These feelings are normal and part of growing up. What's Private? Private means when you are alone. Your bedroom and the bathroom are private places. You also have private parts of your body, which are covered by your bra and underpants. Some of the changes that come with puberty need to be taken care of in private. What to Do in Private Touch yourself. It's OK to touch your private parts when you are alone in the bathroom or your bedroom with the door closed. Do not touch your private parts when in public. Public places are where other people are around, like a classroom, restaurant, or playground. Your mom or dad or doctor may need to check your private area to keep it clean and healthy. No one else should touch your private area, and you should never touch another person's private area. If anyone (even an adult) ever touches your private area in a way that makes you feel bad, say "no!" and tell your mom, dad, or other trusted adult. Changing your pad. When you get your period, you will need to wear a pad in your underwear to catch the blood. You have to change your pad when it smells or is full of blood. Changing your pad is also something you do in private. Your mom, dad, or another trusted adult can teach you how to use pads. Back to Articles Related Articles Girls and Puberty Girls have lots of questions about puberty and growing up. Find all the answers here! Read More Video: Am I Normal? (Girls and Puberty) Girls have lots of questions about the body changes of puberty, especially about breasts and first periods. Watch this video to get some answers! Read More Autism Spectrum Disorder Autism spectrum disorder makes it hard for kids to learn and communicate. Find out more in this article for kids. Read More How to Tell When Someone Is Nice: Answers for Kids With Autism Choose friends who are nice to you. Here's how to tell if someone is nice, or is being mean. Read More Making Friends: Answers for Kids With Autism Sometimes kids with autism want to make new friends, but aren’t sure how to do it. This article can help. Read More What to Say: Answers for Kids With Autism Knowing what to say comes naturally for some kids, but others need some help. Learn how to start a conversation, keep it going, and more. Read More Taking Care of Your Body: Answers for Girls With Autism Learning how to take care of your body is part of growing up. Here's what you need to do to stay healthy and clean. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.