The 5 Stages of Puberty in Boys

How Your Son Develops Into a Young Man

Teenage boy exercising with dumb bell
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A boy goes through many important changes during puberty. His body beefs up, his voice cracks, he becomes stronger, and he begins to mature sexually. Before you know it, your boy has become a young man.

Signs of Puberty in Boys

Boys mature a little slower than girls. Puberty typically begins around age 9 for boys. Some boys will mature faster than their peers, and some physical changes may be more gradual than others.

A number of the physical changes are very personal. As a parent, you may not notice them, but your son will. His penis and testicles will begin to grow, as will pubic hair. Soon, he may begin to have sexual thoughts and wet dreams. These may be embarrassing experiences for him and he will likely keep much of this private.

Externally, you may notice your son's body begin to grow. He will get taller, his shoulders will broaden, and muscles will develop more definition. He will become noticeably stronger and can take advantage of that by beginning a regular workout routine.

Personal hygiene is probably one of the biggest changes for young boys. It may have been hard to get him to wash his hands or take a shower, but now he is going to want to pay attention to these things. He may soon come to you and ask about shaving the peach fuzz from his face or ask about antiperspirants because he is sweating more than usual. His hormones will produce more oil on his skin and he may be prone to acne breakouts. This is the perfect time to introduce him to good skin care routines.

Talking to Your Son

Your little boy is growing up and this also means that he may open up to you less often. It is common for teenage boys to become less talkative and withdraw from their parents. Keep the lines of communication open and talk to your son about the changes he's experiencing. Stay connected to his interests and talk to him about sports, school or whatever he enjoys. It will help him feel comfortable about coming to you when he needs to talk about something important.

Tanner Stages of Puberty in Boys

Teen boys will develop physically in certain stages, often called Tanner stages. Your pediatrician or family health care provider can determine what stage your teen is at and if it is expected for his age.

  • Sexual Maturity Rating 1. Prepuberty stage. The testes are small and the phallus (penis) is child-like. There is no public hair.
  • Sexual Maturity Rating 2. From 9 years old to 14 years old. The testicles grow in volume and size. The penis has no to slight enlargement. The scrotum becomes reddened, thinner, and larger. A few pubic hairs become visible and they are long, straight and slightly dark.
  • Sexual Maturity Rating 3. From 10 years old to 14 years old. The testes continue to grow in volume and size. The penis becomes longer. The scrotum continues to enlarge. Pubic hairs become darker and curlier and more of them appear.
  • Sexual Maturity Rating 4. From 11 years old to 15 years old. The testicles continue to grow. The penis continues to grow in length and now becomes thicker. The scrotum grows larger and also darkens. Pubic hair is coarse, thicker, and curly like adult hair but there are fewer hairs than an adult.
  • Sexual Maturity Rating 5. The testicles are of an adult size (greater than 20 ml in volume). The scrotum and penis are of adult size and form. The pubic hair is of normal adult distribution and volume.

    A Word From Verywell

    If you have questions or concerns about how your son is progressing through puberty, talk to his health care provider. Your provider can determine if your teen is growing and developing as expected and help you understand the biology that is at work.

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    View Article Sources
    • Kliegman, RM. et. al. Nelson Textbook of Pediatrics. Elsevier; 2016.
    • Neinstein LS, Katzman DK. Neinsteins Adolescent and Young Adult Health Care: a Practical Guide. Philadelphia: Wolters Kluwer; 2016.