As you get older, your body changes. This is part of growing up. It's called puberty. What Is Puberty? Puberty is when a person's body changes as they go from being a kid to an adult. Boys become men. Girls become women. The changes of puberty happen slowly. When things change, it can feel a little scary, but knowing what to expect can help you feel better. When you have questions, ask your mom, dad, doctor, or another trusted adult. What Will Happen to My Body? During puberty, your body goes through many changes. This is healthy and normal. First, the skin on your face will get oily and you may get pimples on your face. Your voice will sound lower. Hair will grow on body parts other than your head. It will grow on your face, under your arms, on your chest, and in your private area (the part of your body covered by underwear.) Your arms and legs will get hairier. When you sweat, it will smell stinky, especially under your arms. Your penis and testicles (balls) will get bigger. Sometimes your penis will get bigger and hard. This is called an erection. Why Does My Penis Get Hard? Sometimes erections just happen. Other times, they happen when you touch your penis or something rubs against it. It's called ejaculation when a sticky liquid called semen comes out of your penis. When you ejaculate at night in your sleep, it is called a wet dream. Erections, ejaculation, and wet dreams are a normal part of puberty. 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 a 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 underwear. 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. Ejaculations and wet dreams happen in private. 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. When you are older and ready to have a girlfriend or boyfriend, talk to a parent, doctor, or other trusted adult to learn about sex and healthy relationships. Back to Articles Related Articles Taking Care of Your Body: Answers for Boys With Autism When you're a teen, your body changes — this is part of growing up. You will have to learn new routines to keep yourself clean and healthy. Here's what to expect. Read More Autism Spectrum Disorder Autism spectrum disorder can make communicating and interacting with other people difficult. Find out more. Read More Everything You Wanted to Know About Puberty Voice cracking? Clothes don't fit? Puberty can be a confusing time, but learning about it doesn't have to be. Read all about it. Read More Male Reproductive System What makes up a guy's reproductive system and how does it develop? Find the answers to these questions and more. Read More How to Tell When Someone Is Nice: Answers for Teens With Autism Spend time with people who are nice to you. Here's how to tell when someone is being nice, or being mean. Read More Making Friends: Answers for Teens With Autism You might want to make new friends, but aren’t sure how to do it. This article for teens with autism can help. Read More What to Say: Answers for Teens With Autism Knowing what to say comes naturally for some people, but others need some help. Here’s advice for teens who want to learn how to get along with people. Read More Is My Penis Normal? Just about every guy wonders about the size of his penis at one time or another. 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.