Puberty & Sexual Development

The basis or foundation for a person’s sexual development and sexual health starts at birth and continues throughout childhood. However, many changes—sexual, physical, emotional, social and developmental—that start at puberty and continue through the teen years.

By learning about the changes to expect during puberty and the teen years, you’ll be better prepared to talk to your child about the changes they’ll go through, make sure they understand that the changes are normal and healthy, and answer questions they have openly, honestly and correctly.

The information below  outlines some information on puberty, menstruation and human sexual response.


Puberty is the time where sexual organs mature and having a baby becomes possible. Puberty, and the changes involved, happens at different times for different people. Females tend to go through puberty earlier than males. While it can happen earlier or later:

  • females may notice the changes begin between 8 and 16 years
  • males may notice the changes begin between 9 and 14 years

Some children go through puberty quickly,  others more slowly. Overall, puberty usually lasts 3 or 4 years. To learn more about the emotional, social and developmental changes children will go through, see Information by Age.

Here are some physical and sexual changes your child can expect. Give your child the facts about their body and an understanding of puberty—this will help them to understand that these changes are normal and healthy before it happens.

Both Females and Males

  • they will start growing taller and will gain weight (both fat and muscle)
  • their skin will start making more oil and acne on their face, upper back and/or chest
  • they will grow hair on their legs, underarms and pubic area, and this will continue to grow thicker and darker during puberty
  • they will start to sweat more and may need to start using antiperspirant/deodorant
  • they will have a new desire for sexual experiences which are brought on by changes in hormones.
  • they may masturbate

Females Only

  • they will grow taller faster than most of the boys, and will usually reach their adult height by age 16 or 17
  • their breasts will start to grow and they may experience soreness under the nipples
  • they will start to gain weight in their hips, buttocks, legs and stomach
  • their menstrual period will start and will eventually become regular—usually females get their period 2 to 2.5 years after their breasts start to grow
  • they will start to have white, mucous-like discharge from their vagina

Males Only

  • their shoulders will grow wider
  • body hair and facial hair will start to grow
  • their penis, scrotum, and testes will grow
  • ejaculation and nocturnal emissions (‘wet dreams’) occur and sperm production begins or continues
  • voice starts to crack and becomes deeper
  • they may have swelling under the nipples (this growth usually goes away by the end of puberty)
  • they are capable of erections and ejaculation (sometimes during sleep) as sperm production begins


Menstruation (‘having your period’) is a physical change that will start some time during puberty.

A female’s body begins releasing 1 egg (ovum) from the ovaries each month. If this egg is fertilized by a male sperm, it grows into a baby.

To get ready for the fertilized egg, the uterus builds up a thick lining of blood and tissue. This lining is where the fertilized egg would grow into a baby.

If the egg isn’t fertilized by sperm, the egg and the lining of the uterus leaves the body through the vagina (menstruation) and the cycle starts all over again.

The cycle is between 24 and 38 days. A period is the time the blood and tissue drain though the vagina. It usually lasts between 3 and 5 days. Every person is different. There’s no right or wrong time for when menstruation will begin.

Here are some things you can talk about to make sure your child’s prepared:

  • Talk about menstruation with your child before their periods start. Make sure your child understands that periods are a normal part of growing and changing and they can keep doing with usual activities.
  • Talk about what premenstrual syndrome (PMS) is and what they might feel. For example, some teens get mild to strong cramps. Using a hot water bottle and/or taking ibuprofen (e.g., Advil® or Motrin®) may help.
  • Talk about why hygiene and being clean are important, especially changing pads regularly.

Other things you can do are to:

  • use a calendar or diary to keep track of their cycle and help plan for the next one.
  • have a supply of pads ready to show your child (use a doll to practise with).
  • keep a hygiene pack (clean underwear, pads, wipes) in a nearby place (backpack or locker) in case your child has an unexpected period.
  • help your child think about clothing choices (e.g., don’t wear white pants when their period is due).

Helpful Tools


A Hard Pill to Swallow

Julie accidently drops something she wishes her dad hadn’t seen. How does dad respond? Watch our webisode to find out; and learn how to start the conversation on sexual health.


The Hair Down There

Ryan asks mom about ‘the hair down there’ for the first time. How will she respond? Watch our webisode to find out; and learn how to start the conversation on sexual health.

Back to top