Guys' FAQ About Puberty

Medically Reviewed by Carol DerSarkissian, MD on November 03, 2021
6 min read

Puberty is a time of sexual growth and development. It's a time when your body starts to change and you begin to look more like a grown-up. Boys start to look like young men. Girls start to look more "womanly."

Puberty is a normal and natural event. It's an important step towards becoming an adult.

Your mom, dad, or your doctor may say you are "going through" puberty. That's because puberty actually refers to several changes that happen over a few years. Sometimes, people say you have "hit" puberty.

Everyone is different, but puberty usually starts in boys between the ages of 10 and 14. You and your friends may not start puberty at the same time. That's normal.

In boys, puberty is considered "precocious" -- or early -- if it begins before or about age 9. Puberty is considered "delayed" when there are still no signs of sexual growth or development by the time a boy reaches age 14.

Puberty begins when your body starts to make a lot of chemicals called sex hormones. This flood of hormones causes the changes you notice during puberty.

In boys, the main sex hormone is testosterone. This hormone is made in your testicles, which are inside the loose sac under your penis. Testosterone helps fuel puberty. Your testicles also produce sperm cells, the cells that make it possible to get a girl pregnant.

The changes that occur in puberty happen in boys over a period of several years. Here are some of the changes you can expect -- and the average age when they happen.

But remember, these are just average ages. The exact schedule you follow may be different than it is for other boys you know.

  • Testicles start to grow, usually between the ages of 11 and 12.
  • Pubic hair -- the hair around your penis and testicles -- often starts to appear when a boy is 12.
  • The penis starts to grow in size often around the age of 13.
  • Also around age13, you may notice a temporary growth in the size of your breasts.
  • A boy's voice starts "cracking" around the age of 13.
  • You may have a growth spurt at about 13 1/2.
  • When you're 14, you may notice hair growing in your armpits.
  • Also at age14, boys often start having wet dreams. That's when semen comes out of your penis while you sleep.
  • The average age for boys to get their "adult" voice is 15.
  • At 15, you may notice you are getting a moustache.
  • By age 16, you may notice that your beard has started to grow.


The first thing you will probably notice is that your testicles are getting bigger. The next thing you're likely to notice is that your penis has started to grow and get longer. It may also get hard when you touch it or rub against something. This is called an erection.

Sometimes you can get an erection when you think of something that's sexually exciting. It can also happen for no reason at all.

Your penis and testicles will continue to grow until you get to the end of puberty.

Increased hormones cause you to sweat a lot more. This can make your body pretty stinky, especially under the arms or between your legs.

Body odor starts early in puberty. Using an antiperspirant/deodorant can help control sweat and stinky odors.

Try using an antibacterial soap when you take a bath or shower. This can help prevent bacteria that can lead to body odor.

The hormones in puberty will cause your vocal cords to get thicker and longer. One day, your high-pitched voice will suddenly "crack." This is normal and will eventually stop. When it does, your voice will be deeper, and it will stay that way.

Your voice won't change, though, until you are almost done with puberty.

A growth spurt means your body is changing more and more into a grown-up. You will know when this happens. Your baby face will slowly look more adult-like. Your clothes and shoes will feel tighter. You will gain weight. You will get stronger as your muscles grow bigger.

The peak growth spurt for boys usually happens about two years after puberty starts. When it does, you will have fuller, broader shoulders and bigger feet and hands. One sign that a growth spurt is starting is a rapid increase in shoe size.

Kids going through puberty usually grow about 4 inches taller every year until they turn 17. After age 17, your height probably won't change. About 25% of a person's lifetime growth in height happens during puberty.

How tall you become usually depends on how tall your parents are. If you have tall parents, you'll probably be taller than average. If your parents are short, chances are you will be, too.

A growth spurt can also make you feel hungry all the time. That's normal. A growing body needs fuel. Just make sure you eat healthy foods and snacks.

You'll see hair first between your legs near your private parts. This is called the pubic area. Soon, you'll spot hair on your legs, underarms, and chest. As you continue through puberty, this hair will get thicker and curlier.

If you still have baby-smooth skin on your face, don't worry. Facial hair grows later on in puberty. But soon enough you'll have a hairy "5 o'clock shadow" and will be asking to borrow your dad's electric razor.

The flood of hormones released by your body during puberty can make you sweat -- a lot. Puberty also makes the oil glands in your skin more active. Together, these two things can trigger pimples and zits. Your doctor calls this "acne."

Keeping your face and body clean can help. But if your acne is very bad, ask your mom or dad to make a doctor's appointment for you. Sometimes, medicine can help clear up severe acne and prevent scarring.

Some kids start puberty very early. If your testicles or pubic hair grow before age 9, you have what is called "precocious puberty." (In girls, precocious puberty is when they grow breasts before age 8.)

Obesity can cause early puberty. Sometimes a doctor can't tell why a boy starts puberty early.

If you are concerned about your changing body, writing things down in a journal can help. Your mom or dad will usually be able to tell when you have entered puberty or if you haven't. But tell your parents if anything troubles you or you think the changes aren't right.

Puberty doesn't just mean body changes. All those hormones racing through your body can cause pretty strong mood swings.

It's normal to feel a bit confused or overwhelmed by all the changes going on in your life. You may also find that you're a lot more aware about and interested in sex.

Talking to your friends or family about your feelings and concerns can help. You will probably learn that your friends are feeling a lot of the same things. Don't worry. After a while, your hormones will balance out, and you probably won't feel so moody.

After puberty is finished, you are considered "sexually mature." That means your body has gone through the changes needed to allow you to make a baby.

If you have sex, even before puberty ends, you can get a girl pregnant. That's because you start making sperm early in puberty. You should always wear a condom if you are going to have sex. Condoms not only help prevent unwanted pregnancies, they help protect you from getting sexually transmitted diseases (STDs) like herpes and HIV/AIDS.