Guys' puberty

Do you have questions about what’s going on with your body? Why your arms suddenly seem too long or your voice is cracking? Why you have acne, or why you’re feeling certain emotions?

Physical changes and emotional changes are a big part of puberty – the time when your body is changing from the body of a child to the body of an adult.

For boys, this process usually begins between ages 10 and 12 and may continue for up to 4 years.

During puberty the changes your body undergoes will be more rapid and dramatic than at any other time in your life. You might find that you develop at a different rate from your friends – so don’t worry if you’re the only guy you know who is/isn’t shaving or if you’re the shortest/tallest in your class. Your development during puberty is unique and right for you.

If you want more information on puberty and the changes happening to your body, talk to a trusted adult or call Kids Help Phone at 1-800-668-6868 and talk to one of our professional counsellors.

Physical changes

Some time before signs of puberty are visible, the pituitary gland at the base of the brain begins to produce chemicals called hormones which set off a chain reaction in the body. In boys, they stimulate the testes (testicles, balls) to produce the male hormone testosterone. This affects the development of your whole body:

  • You grow taller and broader and muscles develop
  • Your larynx (Adam’s apple) gets bigger and your voice begins to “break,” eventually becoming deeper
  • Your testicles become larger to allow your reproductive system to mature and become operational (it is normal for a boy’s two testicles to be different sizes)
  • Sebaceous glands grow larger and produce sebum which can cause acne (pimples)
  • You can become sexually aroused quite easily – a thick whitish fluid produced by the testicles is pumped out of the end of the penis at the peak of sexual excitement (an ejaculation). Each ejaculate can contain 200-500 million sperm. Ejaculation can happen even when you’re sleeping.
  • You start to grow hair under your arms, on your chest and in your pubic area
  • Your sweat glands start developing and produce smells called body odour
  • Some boys put on weight just before their growth spurt. This added padding can sometimes look like breasts (a condition called gynaecomastia) - it’s normal and nothing to worry about and it should go away. If not, or if you are really worried, see your doctor.

One of the most significant changes during puberty is the maturing of your reproductive system. It’s important for you to know that beginning in puberty, and for the rest of your life, it is possible for a girl or woman to become pregnant if you have sexual intercourse with her. Conception occurs when a sperm and ovum (egg) unite. This leads to pregnancy. It is also possible for semen/sperm deposited on the outside of the opening of the vagina to swim in and cause a pregnancy.

For more information on sex, see our sections on Dating and Sexuality and dating.

Emotional Changes

There are also lots of emotional changes during puberty. You may feel moody and depressed one minute and enthusiastic and excited the next. These rapid changes in your mood are normal

Last Reviewed September 2012 by the Kids Help Phone Counselling Team

link embellishment

Resources Around Me

Find sexual health support services near you

Enter a city.

loading animation

    How helpful was this page?

    Poor Excellent