Testosterone is the main hormone responsible for the changes in boys.
It's completely normal for you to experience puberty at any point between the ages of 8 and 14, and these are some of the changes you may notice.
1. Shoulders get wider
Your body is filling out and changing shape during puberty, so you’ll notice your shoulders become wider.
2. Muscles get bigger and stronger
Your muscle mass is also building during puberty, so you’ll notice your muscles grow and strength improve, particularly your upper body strength.
3. Voice starts to change
Your voice will ‘break’ as you go through puberty and will become permanently deeper.
During this process, you might find that your voice is very deep one minute and then goes very high the next. This is completely normal.
4. Penis and testicles gets larger
Your penis and testicles will grow in size during puberty, and your scrotum will gradually become darker in colour.
5. You may start to get erections
This is when your penis goes hard and stiff – and can happen at any time.
6. Testicles start to produce sperm
Semen, which is made up of sperm and other bodily fluids, might be released when you have an erection.
This is called ejaculation. Once sperm is made and ejaculation happens, if you had sex without protection you could get someone pregnant.
7. You might have 'wet dreams'
This is when you ejaculate and release semen in your sleep. This is a completely normal part of puberty.
how to get help
If you have any more questions on this area or would like to speak to somebody about this topic, have a look at the links or search for your local services in the blue box below. Alternatively you can always contact your public health nurse.
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Find out what services are available to you in your area. Remember your school nurse is always there to give you confidential help and support.