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Puberty for Boys



  • Puberty starts with a change in hormones that causes your body to change from a boy’s body into a man's body. You will grow pubic hair, underarm hair, and facial hair. Your voice will deepen, your muscles will get bigger and stronger, and your body will make sperm.
  • As you go through puberty, you also start to have a lot of different feelings such as wanting more independence and having strong sexual urges.
  • Talk to your parents or healthcare provider if you have questions or concerns.


Puberty is the time when your body changes from a boy’s body into a man's body.

How does puberty start?

Puberty starts with a change in your hormones. Because of a change in hormones released from your brain, your testicles start making testosterone. Testosterone is the main hormone that starts the changes that happen when boys go through puberty.

When does puberty start?

Boys may start puberty as early as age 9 years or as late as age 14. Usually it takes 3 to 4 years for your body to complete the changes into a man’s body.

How do I know when puberty has started?

The first thing you may notice is pubic hair. Soon after pubic hair starts growing in the area around your penis, your penis will get longer and thicker. Your testicles will also get bigger. The testicles make sperm as well as testosterone. If you have sex, the sperm can fertilize a woman’s egg and make a baby. The testicles are in the scrotum, which is the sac of loose skin below the penis. As you mature, the scrotum will hang lower and get looser.

In addition to pubic hair, you will start to have hair under your arms and more hair on your legs. You will have more body odor, so you may want to bathe more often and start using deodorant.

Your voice will change. Before your voice gets deeper, it may go through a squeaky period. You may get embarrassed by it, but it usually doesn't last more than 6 months.

Testosterone will make your muscles get bigger and stronger even if you don't increase your physical activity.

Towards the end of puberty, you will have a growth spurt. You may grow 4 to 6 inches taller in one year. Your beard will start to grow. Hair may also grow on your chest, stomach, and back.

What are erections?

Boys can get erections (a stiff penis) at any age, but during puberty, you start having them more often. Erections usually happen when you have sexual thoughts or physical contact with someone you are attracted to. These things make more blood flow into the penis. Erections can also happen when you masturbate (use your hand to stroke your penis). You may also have erections without thinking or doing anything. Focusing your attention on something else or doing a different physical activity, such as running or taking a cold shower, can help make an erection go away.

What are wet dreams?

As your body is developing, hormones from the brain tell the testicles to make sperm. Your body will make millions of sperm each day. Your body will also make fluid that stores the sperm. This fluid combined with sperm is called semen. Semen can be stored for awhile, but after a time it needs to be released. Hormones signal the penis to have an erection and then to release the semen. This can happen while you are sleeping. You may have romantic or sexual dreams when it happens and these dreams are called wet dreams. Wet dreams are normal. They can happen a few times a week, a few times a month, or maybe not at all. They are a normal part of growing up.

What is masturbation?

Masturbating is touching, rubbing, or stroking your penis for pleasure. The penis will get erect and the touching or rubbing may lead to the release of semen. It can feel good and can release tension. By the early to middle part of puberty, many boys start masturbating. You may masturbate several times a day, once a month, or not at all. It’s a natural way to explore your body and is normal. People often joke about it, but it’s important to know that there are no bad things that happen from masturbating.

What about acne?

One part of puberty that teenagers don't like is acne. You may have heard that acne is caused by not washing your face or from eating greasy food or sweets. There’s no proof that these things cause acne. It’s caused by your changing hormones and is a normal part of growing up. Some boys may not have much acne, but for others it may be worse. You can get medicines to treat mild acne without a prescription. If your acne seems to be more serious, you may want to see your healthcare provider for medicine to help treat it.

What are the emotional changes of puberty?

As you go through puberty, you start to have a lot of different feelings. You are trying to figure out your place in the world. You become more independent and start doing things without your parents. You may be influenced by your friends' ideas and feel pressure to do things that you may not want to do such as smoking and using e-cigarettes, drugs, or alcohol. This is a time to start sorting out your values and decide what is right and wrong.

As part of this, you may start to have strong sexual urges. You may have romantic feelings for someone and start dating. You may feel like you are in love one day and not the next. It is natural to have feelings that change quickly. You may start thinking about having sex. Take time to think through your decision before you have sex. You need to think about the physical and emotional risks you will be taking. If you decide to have sexual intercourse or oral sex (putting your mouth on a partner's genitals), it’s important to talk with your partner about what you are doing and the risks involved. If your sexual partner is a female, she could get pregnant or you could get an infection from sex. Having sex with more than one partner increases these risks. The only way to prevent pregnancy or a sexually transmitted infection 100% of the time is to not have sex.

If you decide to have sex with a female, talk to your partner about birth control. Latex condoms are a form of birth control that helps prevent pregnancy and also protects you and your partner from some infections.

Who can I talk to about these changes?

Try talking to your parents or other adults about your questions or concerns. Parents can be your best resource and strongest support, but you may feel distanced from them and uncomfortable talking with them. Your parents may feel the same way. Remember that your culture, music, and clothing styles are different from what your parents are used to. Your parents may not seem to be in touch with your world, but they really want to know what you are feeling and going through. Be open when they ask you about things such as sex, drugs, and friendships. If you feel like your parents don’t understand your needs, talk to them about it and ask them if you can spend more time together. You may also be able to talk with your healthcare provider, a trusted relative, friend, or teacher about the changes you are noticing and feeling.

Developed by Change Healthcare.
Pediatric Advisor 2022.1 published by Change Healthcare.
Last modified: 2022-01-03
Last reviewed: 2020-01-09
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2022 Change Healthcare LLC and/or one of its subsidiaries
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