Coming of Age: Puberty's Timeline

If you’re the parent of an adolescent, then obviously, you’ve experienced puberty for yourself and know a thing or two about the process. But, how much do you really know about what’s going on in your child’s body? A solid understanding of what goes on behind the scenes can help you guide your child through this overwhelming time with empathy and compassion.

Mother and daughter sitting on the couch, looking at a mobile device









A guide to puberty in girls

All girls are different, and these age ranges are just a guide to the average ages that your daughter may experience the signs of puberty.

Around ages 8-10

The first sign of puberty in girls is often the beginnings of breast development. They may grow unevenly at first, but this is normal and doesn’t mean she’ll always be lopsided. This is often an awkward time for girls—both physically and emotionally—and she may be embarrassed about her new curves. Now is really not the time to tease her or call attention to the changes in front of others.

About a year before her first period, she may notice a bit of yellow or white vaginal discharge—as long as there is no itching or bad odor, it’s nothing to worry about. This would be a good time to talk about menstruation, if you haven’t already, because the bleeding can be scary if it’s not expected. You may also want to arm her with a pad and some extra underwear, so she’s prepared when the time comes.

Around ages 11-13

This is the average age for a girl’s first period, although anywhere between ages 8 and 16 are still within the normal range. Her breasts will continue to grow, and she’ll develop a curvier shape in her legs and hips. It’s important to make sure she understands that this growth doesn’t make her fat or ugly or any other negative term she might think of. Also around this time, underarm glands may become more active, and normal body odor will be the signal to start wearing deodorant.

Around ages 12-15

Girls typically grow hair under their arms well after they start getting their periods, and a pretty major growth spurt is also to be expected. An increase in oil production may cause acne on the face, chest or back, so teaching her how to care for her skin will be important.

Throughout puberty

The life of an adolescent girl is hard! Especially if she’s one of the first (or last) of her friends to start these changes, the stress and emotions can sometimes be overwhelming. Mood swings are common, as is low self-esteem, but you can both take comfort in knowing that this is a relatively short time in her life.

Father and son playing on a tablet









A guide to puberty in boys

Boys typically go through puberty a little bit later than girls, on average. Again, all boys are different, and these age ranges are just a guide to the “average” ages during puberty.

Around ages 10-12

The first sign of puberty in boys usually involves the growth of the testicles, along with a thinning and reddening of the scrotum. Pubic hair will also begin to develop around the base of the penis.

Around ages 11-13

The penis and testicles begin to grow more rapidly, the scrotum darkens, pubic hair gets thicker and underarm hair appears. Your son will probably begin to sweat more, with a noticeable odor, so it’s a good time to provide deodorant. Some more obvious (and sometimes embarrassing) signs of puberty may include:

  • Voice changes, like “cracking” and sudden changes from a very high to a much deeper voice
  • Acne on his face, chest or back
  • Swelling of breast tissue (these are not “man boobs” and they will go away fairly quickly)

A potential issue that may come up is accidental ejaculation of semen while he’s sleeping. This can be humiliating for a child, especially if he doesn’t know what to expect, and he may think that he has wet his bed. Talking to him before this occurs might help to ease his embarrassment (even though the conversation itself may be awkward), making sure that he knows it’s normal and can’t really be prevented.

Around ages 14-16

Growth spurts are frequent, and your child may have already experienced a couple. Expect him to grow about three inches every year for a few years (although it could be much more rapid at times). Also expect him to eat everything in sight to fuel his growing body. Body hair will be growing (seemingly everywhere!) and he’ll likely start needing to shave within the next year or two.

Throughout puberty

Raging hormones may render your sweet little boy unrecognizable at times. He may have periods of moodiness, low self-esteem and depression, and he may have sudden bouts of aggression. Of course, you want to address any behaviors or feelings that may be harmful to your son (or to others), but both of you should understand that many of these feelings are just part of growing up, and things should calm down pretty soon.