Puberty is the time in a person’s life in which they become sexually mature from a physical perspective. It is a process that usually happens between ages 10 and 14 for girls, and ages 12 and 16 for boys. Puberty causes physical changes, and affects boys and girls differently.

Talking to your child about puberty is an important job for parents, as not all information comes from reliable sources. Don’t wait for your child to initiate a conversation regarding puberty. As a parent, it is your job to try to discuss puberty as openly as possible.

Starting the conversation about puberty

It can be difficult to know how to start to talk with your child about puberty. Many parents find that it is helpful and less uncomfortable to have smaller more frequent conversations.

Start early – as early as your child starts asking questions about his or her body parts – and go little by little. It is best to start talking about the changes before your daughter/son starts experiencing them.

By the time kids are 8 years old, they should know what emotional and physical changes are associated with puberty.

When discussing puberty, it is important to be reassuring. It can be helpful to let your child know that everyone goes through these changes. It is also important to let your child know that the timing of these changes can greatly vary.

Many kids receive some sex education at school and it is a good idea to review these lessons with your child as he or she may have lingering questions about certain topics. Talking to your child about puberty can be easier if you are confident on the subject so make sure your own questions are answered first. If you are nervous, it can help to practice what you want to say first. Also, you can let your child know that it is an important talk to have, even though it can be uncomfortable to discuss. 

Discussing physical growth can transition to discussing other changes in your child’s body. One way to start the conversation is by admiring how much your child is growing. You can say “you are growing up so fast and I am so proud of the person you are becoming. As you grow, you may notice some other changes in your body.”

Having a book about puberty  can also be a way to start the conversation. You can read it with your child together, or they may prefer to read it on their own.

Some families find it helpful to have a journal where your child can write down his or her questions and leave the journal in a special place for you. You can then write answers back and leave it for him or her.  

You can also discuss what you remember going through. “When I was your age, I remember feeling _____” or “I was most worried about____.”

Be available for questions. Be sure to use direct honest language. And use correct anatomical terms, not slang, when discussing body parts.

Physical changes to expect in boys during puberty

  • Scrotum: The testicles grow in size and the skin of the scrotum darkens, enlarges, hangs down from the body, and becomes dotted with tiny bumps. These bumps are hair follicles. In most boys, one testicle (usually the left) hangs lower than the other.
  • Pubic hair: Initially, a few light-colored downy hairs appear at the base of the penis. The pubic hair soon will turn darker, curlier, and coarser in texture. Over the next few years it will cover the pubic region and spread towards the thighs. A thin line of hair also travels up to the navel. Roughly two years after the appearance of pubic hair, sparse hair begins to sprout on the face, legs, arms, underarms, and later the chest.
  • Changing body shape: Just prior to and at the onset of puberty, boys tend to look a little chubby and gangly with long arms and legs compared to the trunk. They start to experience a growth spurt as they progress further into puberty. Body proportions change during this spurt, there is rapid growth of the trunk and at the legs to some extent too. Boys will accumulate more muscle mass throughout puberty. Some boys experience a temporary breast growth during puberty. This condition (called gynecomastia) is caused by changing hormone levels during puberty and usually disappears within a few months to a couple years.
  • Penis growth: A boy may have adult-sized genitalia as early as 13 and as late as 18 years old. The penis first grows in length, then in width. Some boys may notice that peers have foreskin while others don’t. Boys may have questions about circumcision, and you can explain that it is a medical procedure performed due to parents’ choice or religious custom.
  • Erections, masturbation, and nocturnal emissions: Boys are capable of procreation with their first ejaculation, which occurs about one year after the testicles begin to enlarge. Erections can be unpredictable during puberty and often happen during inopportune times. You may have to tell your teen there is not much he can do to suppress the erections but, with the passage of time, they will become less frequent. A child’s first ejaculation may occur by conscious masturbation or may occur at night while he is asleep. Your child may wake with wet pajamas or sheets and wonder if he wet the bed. You can explain that this phenomenon happens to all boys during puberty and will stop as he gets older. Also note that masturbation is harmless and normal, as long as it is done in private.
  • Voice change: Just after the growth spurt, the voice box (larynx) and vocal cords enlarge. As the voice deepens, a boy’s voice may occasionally crack. Once the larynx reaches adult size, the cracking stops.

Physical changes to expect in girls during puberty

  • Breast development: Breast buds are the first evidence of puberty in girls. Breast buds are nickel-sized lumps behind one or both nipples that typically occur around age 9 or 10. The breast buds are firm to the touch and sometimes tender or sore. In the early stages of puberty, one breast may be noticeably larger than the other. Breast size usually evens out but most adult women’s breasts are slightly different in size. Breast size is different from girl to girl and the size and shape of a girl’s breasts will change as she continues to develop. Parents or young girls may ask if they should start wearing training bras. Training bras are not necessary to provide support to growing breast tissue.Some girls may feel self-conscious if they begin to develop earlier than their peers and may decide to wear loose-fitting clothing. The AAP suggests that parents be willing to purchase a training bra if the adolescent asks for one to act as a barrier.
  • Pubic hair: The appearance of pubic hair is the second sign of puberty for most girls. The hair is initially sparse and straight, but eventually fills in and becomes darker, curlier, and coarser. Over the next few years, the pubic hair will take a triangular shape and finally will spread to the inner thighs.
  • Changing body shape: Preadolescent females acquire “baby fat,” which may give them a more rounded belly. This can cause anxiety for girls, who live in a world with thin super models and unrealistically proportioned dolls. However, the deposition of adipose tissue (fat) around the middle is part of normal development and the body will soon redistribute the fat to the breasts and hips.
  • Menstruation: The time to start discussing periods with your daughter is when breasts start to develop. The first menstrual period usually occurs 1 ½ – 3 years after breasts begin to develop. Girls often have misconceptions and fears associated with menstruation and it is important to explain the concept of ovulation and menstruation before it occurs. Prepare your daughter in advance by buying pads or tampons and explaining how they are used. Most girls have their first menstrual period around the same age their mothers and older sisters did. Menstrual cycles can be highly irregular in the first couple of years, sometimes with as many as six months passing between periods. However, once periods become regular, there are several conditions that can cause a girl to miss her period. Periods typically last 3 – 7 days and occur every 3 – 5 weeks. The first several periods are almost always painless but, once a girl begins to ovulate, she may experience some discomfort surrounding her period. Common symptoms include bloating, cramping, tender or swollen breasts, mood changes, and headaches. If a girl has not menstruated by age 16 or 17, she should be evaluated by her pediatrician.

Additional Topics:

Deodorant: When adolescents are entering puberty, they may start to notice the development of body odor. They can start to apply deodorant. Deodorants will not block perspiration (or sweating) but can absorb moisture and mask an odor. This differs from an anti-perspirant that contains aluminum. Aluminum blocks the opening of sweat glands.  Using either deodorant or anti-perspirant is acceptable. Teens can use adult deodorant/antiperspirant.  

Additional resources:

Recommended reading:

Books for girls:

  • The Care and Keeping of You 1 (For Younger Girls), an American Girl book
  • The Care and Keeping of You 2 (For Older Girls), an American Girl book
  • The What’s Happening to My Body? Book for Girls by Lynda Madaras
  • Growing Up –It’s a Girl Thing by Mavis Jukes

Books for boys:

  • Guy Stuff: The Body Book for Boysby Cara Natterson
  • What’s Going on Down There? A Boy’s Guide to Growing Up by Karen Gravelle with Nick and Chava Castro
  • What’s Happening to My Body? Book for Boys: A Growing-Up Guide for Parents and Sons by Lynda Madaras
  • The Boy’s Body Book: Everything You Need to Know for Growing Up YOU by Kelli Dunham

Books for both:

  • It's Perfectly Normal: Changing Bodies, Growing Up, Sex, and Sexual Health by Robie Harris

Related resources:


Written by Jen White, MD; reviewed by Sara Laule, MD and Sydney Ryckman, MD

Updated July 2022