Your Son at 15: Milestones

That little boy with the skinned knees and funny grin isn’t little anymore. It may be hard to believe, but your son is 15. He’s probably in his first or second year of high school.

A 15-year-old is an adolescent -- no longer a child, but not yet an adult either.

It’s a time of physical changes, but it’s also a time of big intellectual, social, and emotional development. While it differs a lot from boy to boy, there are common milestones to look for.


At this age, 15-year-old boys continue to grow. They:

  • Eat a lot and are almost always hungry
  • Get taller and more muscular
  • Need lots of sleep
  • Can be clumsy because they’re growing

Sexual changes:

  • Larger penis and testicles that start to make sperm
  • Pubic hair, then underarm and facial hair
  • Deeper voice that sometimes cracks
  • Bigger Adam’s apple


Young children think only about what’s going on at the moment. But by age 15, a boy can think in more complex ways. Look for your son to:

  • Start to set goals for the future
  • Plan for “what if” situations
  • Make more of his own decisions
  • Develop a sense of right and wrong

Understand the effects of his behavior

Emotional and Social

Teens at this age search for identity -- a sense of who they are. They want to be more in control and more independent. Your 15-year-old son may also:

  • Think friends are more important than family
  • Spend less time with parents, and more time with friends or alone
  • Want to argue more and talk less
  • Start to date
  • Become more aware of sexual orientation
  • Feel things deeply
  • Try to understand his own feelings
  • Get sad or depressed. This can lead to problems in school, use of drugs or alcohol, risky sex, and other behaviors

Keep Him Safe

Teens at ages 15-19 have higher rates of death than younger children. Top causes are vehicle crashes, homicide, and suicide. About a quarter of kids age 12-17 have used drugs.

These basic rules can help your son stay safe:

  • Always wear a seatbelt and never use a cell phone while driving.
  • Be careful online and when using social media. Reinforce rules around media use and gaming, including sharing of personal information.
  • Wear safety gear on a bike, rollerblades, or skateboard.
  • Follow family rules, and the law, around alcohol and drug use.
  • Stay away from guns unless you are trained and with an adult who knows gun safety.
  • Understand what can happen if you are sexually active (talk with your son about diseases, pregnancy, respect for girls, and how sex might change the way he feels about himself).


How You Can Help

As a parent, you can do a lot to help your adolescent son. Be ready to talk when he is -- no phones, no TV, just the two of you. Listen quietly and try to understand his point of view. Then offer your own opinion. Don’t laugh at or make fun of what he says.

Other ways to help:

  • Let him know when he does something well.
  • Encourage him to be part of family decision-making.
  • Show interest in his friends, school, and activities.
  • Set rules for use of phones, devices, and social media.
  • Help him understand peer pressure. It can be good or bad.
  • Make sure he knows what to do if he is offered drugs or is pressured to have sex.
  • Encourage your son to volunteer and care about others.
  • Give him his privacy.
  • Be a good role model for choices about sleep, food, and exercise.

Pay attention to signs of suicide. Your son may be at risk if he:

  • Talks about suicide or death
  • Talks about not being around in the future
  • Gives away things he loves
  • Increases his use of drugs or alcohol
  • Has tried suicide before

Don’t leave your son alone if you think there is a chance of suicide. Get help right away.

Milestones to Go

At 15, your son doesn’t need you to help him cross the street. But he does need you to guide him as he moves toward adulthood. If you are concerned about him, talk with a doctor or school counselor.

WebMD Medical Reference Reviewed by Renee A. Alli, MD on April 19, 2019



Cleveland Clinic: “Adolescent Development.”

KidsHealth from Nemours, Growth and Your 13-18-Year-Old: “Changes in


Understood: “Developmental Milestones for Typical High-Schoolers.”

Sutter Health Palo Alto Medical Foundation: “Parents & Teachers: Teen

Growth & Development, Years 15 to 17.”

CDC: “Child Development, Teenagers (15-17 years of age).”

Cleveland Clini:, “Social Development During the Teen Years.”

NorthShore University HealthSystem, Pediatrics: “Teenager (13-18 Years).”

Youth Suicide Prevention Program: “Know the Warning Signs.”

© 2019 WebMD, LLC. All rights reserved.


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