Ages & Stages

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.


Last Updated
Puberty - Ready or Not Expect Some Changes (Copyright © 2010 American Academy of Pediatrics, Updated 3/2012)
The information contained on this Web site 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.