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.
When Will I Start 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.
What Causes Puberty?
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.
What Happens During Puberty?
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 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 a boy to get his "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.