Puberty—Ready or Not Expect Some Big Changes

Puberty is the time in your life when your body starts changing from that of a child to that of an adult. At times you may feel like your body is totally out of control! Your arms, legs, hands, and feet may grow faster than the rest of your body. You may feel a little clumsier than usual.

Compared to your friends you may feel too tall, too short, too fat, or too skinny. You may feel self-conscious about these changes, but many of your friends probably do too.

Everyone goes through puberty, but not always at the same time or exactly in the same way. In general, here's what you can expect.


There's no "right" time for puberty to begin. But girls start a little earlier than boys—usually between 8 and 13 years of age. Puberty for boys usually starts at about 10 to 14 years of age.

What's happening?

Chemicals called hormones will cause many changes in your body.


Girls. The first sign of puberty in most girls is breast development—small, tender lumps under one or both nipples. The soreness goes away as your breasts grow. Don't worry if one breast grows a little faster than the other. By the time your breasts are fully developed, they usually end up being the same size.

When your breasts get larger, you may want to start wearing a bra. Some girls are excited about this. Other girls may feel embarrassed, especially if they are the first of their friends to need a bra. Do what is comfortable for you.

Boys. During puberty, boys may have swelling under their nipples too. If this happens to you, you may worry that you're growing breasts. Don't worry—you're not. This swelling is very common and only temporary. But if you're worried, talk with your pediatrician.

Hair, where?!

Girls & Boys. During puberty, soft hair starts to grow in the pubic area (the area between your legs and around your genitals—vagina or penis). This hair will become thick and very curly. You may also notice hair under your arms and on your legs. Boys might get hair on their faces or chests. Shaving is a personal choice. However, if you shave, use only an electric shaver.


Girls & Boys. Another change that happens during puberty is that your skin gets oilier and you may start to sweat more. This is because your glands are growing too. It's important to wash every day to keep your skin clean. Most people use a deodorant or antiperspirant to keep odor and wetness under control.

Don't be surprised, even if you wash your face every day, that you still get pimples. This is called acne, and it's normal during this time when your hormone levels are high. Almost all teens get acne at one time or another. Whether your case is mild or severe, there are things you can do to keep it under control. For more information on controlling acne, talk with your pediatrician.

Curves and muscles

Girls. As you go through puberty, you'll get taller, your hips will get wider, and your waist will get smaller. Your body also begins to build up fat in your belly, bottom, and legs. This is normal and gives your body the curvier shape of a woman.

Boys. As you go through puberty, you'll get taller, your shoulders will get broader, and as your muscles get bigger, your weight will increase.

Sometimes the weight gain of puberty causes girls and boys to feel so uncomfortable with how they look that they try to lose weight by throwing up, not eating, or taking medicines. This is not a healthy way to lose weight and may make you very sick. If you feel this way, or have tried any of these ways to lose weight, please talk with your parents or your pediatrician.

Does size matter?

Boys. During puberty, the penis and testes get larger. There's also an increase in sex hormones. You may notice you get erections (when the penis gets stiff and hard) more often than before. This is normal. Even though you may feel embarrassed, try to remember that unless you draw attention to it, most people won't even notice your erection. Also, remember that the size of your penis has nothing to do with manliness or sexual functioning.

Wet dreams

Boys. During puberty, your testes begin to produce sperm. This means that during an erection, you may also ejaculate. This is when semen (made up of sperm and other fluids) is released through the penis. This could happen while you are sleeping. You might wake up to find your sheets or pajamas are wet. This is called a nocturnal emission or "wet dream." This is normal and will stop as you get older.


Girls. Your menstrual cycle, or "period," starts during puberty. Most girls get their periods 2 to 21/2 years after their breasts start to grow (between 10–16 years of age).

During puberty, your ovaries begin to release eggs. If an egg connects with sperm from a man's penis (fertilization), it will grow inside your uterus and develop into a baby. To prepare for this, a thick layer of tissue and blood cells builds up in your uterus. If the egg doesn't connect with a sperm, the body does not need these tissues and cells. They turn into a blood-like fluid and flow out of your vagina. Your period is the monthly discharge of this fluid out of the body.

A girl who has started having periods is able to get pregnant, even if she doesn't have a period every month.

You will need to wear some kind of sanitary pad and/or tampon to absorb this fluid and keep it from getting on your clothes. Most periods last from 3 to 7 days. Having your period does not mean you have to avoid any of your normal activities like swimming, horseback riding, or gym class. Exercise can even help get rid of cramps and other discomforts that you may feel during your period.

Voice cracking?

Boys. Your voice will get deeper, but it doesn't happen all at once. It usually starts with your voice cracking. As you keep growing, the cracking will stop and your voice will stay at the lower range.

New feelings

In addition to all the physical changes you will go through during puberty, there are many emotional changes as well. For example, you may start to care more about what other people think about you because you want to be accepted and liked. Your relationships with others may begin to change. Some become more important and some less so. You'll start to separate more from your parents and identify with others your age. You may begin to make decisions that could affect the rest of your life.

At times you may not like the attention of your parents and other adults, but they too are trying to adjust to the changes that you're going through. Many teens feel that their parents don't understand them—this is a normal feeling. It's usually best to let them know (politely) how you feel and then talk things out together.

Also, it's normal to lose your temper more easily and to feel that nobody cares about you. Talk about your feelings with your parents, another trusted adult, or your pediatrician. You may be surprised at how much better you will feel.

Sex and sexuality

During this time, many young people also become more aware of their feminine and masculine sides. A look, a touch, or just thinking about someone may make your heart beat faster and produce a warm, tingling feeling all over. Talking with your parents or pediatrician is a good way to get information and to help you think about how these changes affect you.

You may ask yourself...

  • When should I start dating?

  • When is it OK to kiss?

  • Is it OK to masturbate (stimulate your genitals for sexual pleasure)?

  • How far should I go sexually?

  • When will I be ready to have sexual intercourse?

  • Will having sex help my relationship?

  • If I am attracted to a same-sex friend, does that mean I am gay or lesbian?

  • Is oral sex really sex?

Some answers. . .

Masturbation is normal and won't harm you. Many boys and girls masturbate, many don't. Deciding to become sexually active, however, can be very confusing. On the one hand, you hear so many warnings and dangers about having sex. On the other hand, movies, TV, magazines, even the lyrics in songs all seem to be telling you that having sex is OK.

The fact is, sex is a part of life and, like many parts of life, it can be good or bad. It all depends on you and the choices you make. Take dating, for example. If you and a friend feel ready to start dating and it's OK with your parents, that's fine. You may find yourself in a more serious relationship. But if one of you wants to stop dating, try not to hurt the other person's feelings—just be honest with each other. After a breakup both partners may be sad or angry, but keeping on with normal activities and talking it over with a trusted adult is usually helpful.

Getting close to someone you like is OK too. Holding hands, hugging, and kissing may happen, but they don't have to lead to having sex. Deciding whether to have sex is one of the most important decisions you will ever make. Some good advice is in a publication called Deciding to Wait that your pediatrician can give you. Why not take your time and think it through? Talk with your parents about your family's values. Waiting to have sex until you are older, in a serious relationship, and able to accept the responsibilities that come along with it is a great idea!

And you can avoid becoming pregnant, getting someone pregnant, or getting diseases. There is only one way to avoid pregnancy and infections related to sex, and that is by not having sex. And remember that oral sex is sex. You don't have to worry about pregnancy with oral sex, but you do have to worry about infections like herpes, gonorrhea, HIV (the virus that causes AIDS), and HPV (human papillomavirus—the virus that can cause cancers of the mouth and throat, cervix and genitals in teens and adults).

However, if you decide to have sex, talk with your pediatrician about which type of birth control is best for you and how to protect yourself against sexually transmitted infections.

Taking care of yourself

As you get older, there will be many decisions that you will need to make to ensure that you stay healthy. Eating right, exercising, and getting enough rest are important during puberty because your body is going through many changes. It's also important to feel good about yourself and the decisions you make. Whenever you have questions about your health or your feelings, don't be afraid to share them with your parents and pediatrician.

The persons whose photographs are depicted in this publication are professional models. They have no relation to the issues discussed. Any characters they are portraying are fictional.

Copyright © 2010

American Academy of Pediatrics, Updated 3/12

All rights reserved.

The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

See also:

-Acne—How to Treat and Control It

-Alcohol Abuse

-ASDs Family Handout—Health Care Transition: Moving From Adolescence to Adulthood

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