Mother and daughter smiling together

16, 17 and 18 Year Olds

Understanding Your Child’s Development

Your teen is turning into a young adult. This is an exciting time for them. Their emotions can change quickly as they learn to deal with school, friends and adult expectations. It’s important to try to be an askable adult who’ll be there when your teen needs you. At this age they still have many questions they may not ask.

Speak to your teen as a mature person about shared expectations and accept that you can no longer control what your teen does. You are now more of a guide as they get older. Expect to be challenged about your values. This naturally occurs as your teen develops their independence and their own identity.

To learn more, see Tips for Talking about Sexual Health.


The following is a list of changes your teen may have already gone through or will go through during their remaining teen years.



  • The physical and hormonal changes from puberty continue:
    • continue to grow and gain weight
    • skin is oilier and they may have acne on their face, upper back and/or chest
    • pubic and underarm hair continues to grow and thicken
    • start to sweat more
    • have body odour, and may want to start using an antiperspirant or deodorant
  • Seem to always be hungry and may eat a lot
  • They need more sleep, so it’s okay to let them sleep in on weekends
Teens with ovaries
  • Usually reach their adult height by age 16 or 17
  • Breasts may continue to grow for some; for others, they may be fully developed
  • Still gaining weight, their hips begin to widen and fat padding in the buttocks, legs and stomach increases
  • Menstrual periods and ovulation usually become regular–it’s possible to become pregnant. Some teens don’t have regular periods, especially in the first year or two of menstruating. Some will continue to have irregular periods. If irregular periods continue beyond late puberty, they may need to consult a doctor. It’s important your teen understands that they can still get pregnant even if they had no period. See Missed or Irregular Periods.
  • White, mucous-like discharge from the vagina, particularly mid-menstrual cycle
Teens with testicles
  • Fast growth in height and weight may continue for some but may be slowing for others
  • Shoulders grow wider
  • Body and facial hair still growing
  • Penis, scrotum and testicles are close to, or are fully developed
  • Can have erections and ejaculate, sometimes while sleeping
  • Voice continues to deepen
  • May have swelling under the nipples (usually goes away by the end of puberty)


  • A new desire for sexual experiences brought on by hormone changes
  • Continued interest in romantic relationships
  • More interest in sexuality
  • May be attracted to or have a sexual experience with someone of the same gender. This does not necessarily mean it’s their sexual orientation, but it could. They may also express that they are ‘pansexual’: in other words, they are attracted to whomever they are attracted to, regardless of gender or sex.
  • As they get older, dating relationships have a deeper involvement, with real concern for their partner.
  • Increased physical desire for sexual play and intimacy
  • May masturbate. Sexual fantasies may play a role in their sexuality.


  • May feel confused, have strong emotions and feel anxious about their changing body
  • May become easily upset, be more sensitive or lose their temper more than usual
  • Conforming to their peer group becomes less important
  • Feel stress from more challenging schoolwork
  • Relationships with peers and adults are becoming more stable. Conflicts are likely around issues of independence and self-identity.
  • Have a more realistic and established view of themselves and others

Learning & Thinking (Cognitive)

  • Strong need and desire to assert independence. They may rebel against parents or caregivers.
  • May appear unhappy with expectations from parents but are privately reassured that their parents care enough to put expectations on them
  • Tend to experiment with different roles in their search for self-identity
  • Start to define personal values, using family, peer and societal values as a guide
  • Have an improved ability to think abstractly, consider possible solutions to a problem, and to predict cause-and-effect relationships
  • Future plans become important and start to be put in place
  • Have a need for a supportive environment and for parents to be understanding
  • Are better able to provide reasoning for the choices they make


  • Have a deeper ability for caring, sharing, and developing more intimate relationships
  • Spend less time with parents and more time with friends
  • Still enjoy being part of teams and groups but is more comfortable being their own person

Click the link to learn more about children with Differing Abilities.

What Your Child Needs Your Help to Learn

As children make their way through the teen years, they will keep looking to their friends for answers and information. Being approachable is important so your teen knows they can come to you when they need you. At this age, teens still have many questions that they won’t ask about.

Teens in this stage of development should know all the information from birth to 15 years old, plus know:

For more information, visit our Additional Resources.

To learn more, see Tips for Talking about Sexual Health.

School Curriculum

In Alberta, the health curriculum includes sexual health outcomes beginning in grade four. To learn more, see curriculum overview on our Teacher Portal.

Helpful Tools


Parent Guide (13-18 year olds)

Prepare for the ongoing conversations you'll have with your teen about sexual health. It's never too late to start!


Sexuality Wheel

Explore the dimensions of human sexuality.


Parents' FAQs

See sample questions and answers to help you start conversations about sexual health with your child.


The "Every Body"

Learn about the differences between sex, gender identity, gender expression and sexual orientation.


STI Tool

Learn about some common sexually transmitted infections.


Birth Control Tool

Explore birth control options, how they work, and how well they protect against pregnancy and STIs.


Understanding Consent Video

For ages 12 and up.


Tips for Talking about Sexual Health

Here are some tips for starting or having conversations about sexual health, at any age.

Parent Guide 13-18

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