Signs of Puberty in Tween Boys

Teenage boy listening to music on a mobile phone

ONOKY - Brooke Auchincloss / Brand X Pictures / Getty Images

At some point during the tween years, boys will begin to experience the stages of puberty. This can be complicated for both kids and parents. Knowing what to look for can ease your mind and help your tween through these enormous physical and emotional changes.

Keep in mind that these signs may appear gradually, and it may take several years for your child to completely cycle through all the phases of puberty. In general, 95% of boys begin puberty between the ages of 9 and 14. You can expect to see physical, emotional, and behavioral changes during this time.

Physical Changes

When boys go through puberty, you will notice a number of physical changes. Though girls in 7th and 8th grades can often tower over boys their age, the boys can quickly catch up in high school and frequent growth spurts are not uncommon.

A tween boy may grow 4 inches in 12 months. Three to four years later, when he is done growing, he may have added 13 to 14 inches and 40 pounds. You will also likely notice other physical changes.

Body Hair

Hair growth in the pubic and underarm areas happens during puberty. Your tween may or may not have questions about this. Let them take the reins on this one. At some point, boys also begin to grow chest hair and other body hair will become thicker and sometimes darker.

Body Odor

As hormones increase, boys will begin to sweat more often and body odor often becomes more apparent. Your child may not notice it at first and it's best to be gentle when approaching the subject.

Buy some deodorant and encourage daily showers. While some tweens may resist these ideas at first, they usually take a greater interest in looking and smelling nice as they get older.

Broad Shoulders and Chest Muscles

This can be a subtle change, but boys' upper body muscles begin to develop during puberty. Shoulders become broader and chest muscles more defined. When both of you notice this change, use the opportunity to encourage your child to exercise regularly.

Nocturnal Emissions

It is perfectly normal for boys going through puberty to have involuntary erections and nocturnal emissions or wet dreams. This may be a point of embarrassment for your child. Talk to them about it and explain that it is normal and nothing to be ashamed of. Also, let them know that they will be able to control it as they get older.

Facial Hair

Those small hairs on your tween's upper lip and chin may soon begin to grow longer, thicker and eventually darken. They may even come out of the bathroom one morning and surprise you with a request to buy a razor. Many teens love this change because they view facial hair as a real sign of adulthood.

Acne and Breakouts

Some kids have more of a problem with acne than others, but almost all teenagers will break out with pimples from time to time. This is because their skin becomes oilier due to increased hormones.

Teach your child how to wash their face thoroughly in order to minimize or prevent bad acne. If it becomes unmanageable with over-the-counter products, you may want to see a dermatologist.

Testicular Growth

Testicles grow larger during puberty and one (typically the left) may hang lower than the other. This difference in size is perfectly normal and happens with most people. The skin on the scrotum will also darken, thin, and begin to have tiny hair follicle bumps.

Voice Change

Although it is more likely in the later stages of puberty, your child's voice also will deepen. It is usually after a growth spurt because the voice box has grown as well as the rest of the body.

At first, your child's voice may crack and it may cause some embarrassment. Offer reassurance that this is normal and that everyone experiences these changes.

Emotional Changes

Puberty also is a time of great emotional development. That means you will also see emotional changes in your tween as they mature.

Strong Emotions

Sometimes tweens will experience anxiety or worry about the changes they are going through. They may also feel embarrassment. But others, like a mustache and muscles, may make them happy because they may feel like these are signs that they are becoming an adult.


While your kid may have told you everything that went on each day in elementary school, they may be a little more reserved as they enter puberty. When you ask what happened at school, you may get an answer like "fine" or "nothing."

Your tween also may hang out in their room more and spend less time with the family. This is normal, but it's still important to keep the lines of communication open. You also shouldn't give up on spending time together. Suggest that you watch a movie together or invite them to play a board game. Do what you can to keep the relationship strong.

Romantic Interests

Your child may develop a crush at school or tell you one day that they have a girlfriend or boyfriend. They may show this new interest by being shy or nervous around certain people or by flirting. All of these things are normal.

Try not to tease your child about love interests, but do make sure they understand important concepts like safe sex and consent. Although you have likely already had a talk about sex, it is important to keep this dialogue going. Talking about sex is an ongoing conversation, not a one-time talk.

Mood and Behavior Changes

During puberty, there is approximately a 30-fold increase in testosterone production, which can cause changes in mood and behavior. For instance, you may see increases in aggression, risk-taking, and depression as your tween begins to go through puberty.

Early Puberty

Kids who go through puberty early may experience more mood changes than their peers. They also may struggle more emotionally than their peers. One study found that kids who go through puberty early experience more symptoms of depression than peers who develop at a typical age.

Other research suggests that there are other mental health risks associated with being an early bloomer. In one study, boys who went through early puberty went on to experience higher levels of anxiety, negative self-image, and interpersonal stress than peers who matured later.

When to Call a Doctor

Regardless of the timing of puberty, expect the hormone changes that your child experiences to cause moodiness at times. For the most part, this is normal and may even get worse before it gets getter.

It's important to let your adolescent work through these mood swings and give them space when needed. But don't hesitate to talk to a pediatrician or mental health professional if you think there is a more serious problem like depression or an anxiety disorder.

If you or a loved one are struggling with depression or anxiety, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

A Word From Verywell

Beginning puberty is a big change—for both parents and kids. But with open communication, you can help them navigate these changes in healthy ways. Even when your child appears closed off, cranky, or moody, it is important to still make an effort to connect.

While some moodiness is normal, showing signs of depression like a sense of hopelessness, changes in eating or sleeping habits, or feeling sad much of the time is not. Be sure to get help if your son is experiencing these changes.

7 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Pediatrics. Delayed puberty in boys: Information for parents.

  2. American Academy of Pediatrics. Physical development: What's normal? What's not?.

  3. American Academy of Pediatrics. Physical development in boys: What to expect.

  4. Nemours Children's Health. All about puberty.

  5. Duke SA, Balzer BWR, Steinbeck KS. Testosterone and its effects on human male adolescent mood and behavior: A systematic reviewJ Adolesc Health. 2014;55(3):315-322. doi:10.1016/j.jadohealth.2014.05.007

  6. McGuire TC, McCormick KC, Koch MK, Mendle J. Pubertal maturation and trajectories of depression during early adolescenceFront Psychol. 2019;10:1362. doi:10.3389/fpsyg.2019.01362

  7. American Psychological Association. The Risks of Early Puberty.

By Jennifer O'Donnell
Jennifer O'Donnell holds a BA in English and has training in specific areas regarding tweens, covering parenting for over 8 years.