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What's a hormone?

The onset of puberty occurs anywhere between the ages of 9 - 16. At a signal from the hypothalamus (a region in the brain) and the pituitary gland, the body begins to produce hormones which are chemicals in your body that cause puberty to begin. Hormones help turn your child body into an adult body.

Puberty and Boys

The hormone responsible for all these changes in boys is testosterone. Testosterone makes a boy:

• Grow taller

• Testicles grow larger; one usually hangs lower than the other does.

• Penis grows longer and a little wider; and the penis and scrotum get darker in color.

• Voice gets deeper.

• Breast may be tender and grow a little. This is normal. It usually goes away in a year or so.

• Hair begins to appear in the pubic area, under the arms and on the face.

• Hair and skin become oilier.

• Body odor begins to be produced by sweat glands. Time to start using deodorant and shower or bathe daily.

• Erections. Boys may experience an erection from riding a bicycle, having a dream or fantasy or seeing someone you like or find attractive. It's also normal to experience an erection for no apparent reason.

• Nocturnal emission or wet dream. It is also normal for a boy to experience an ejaculation (a release of sperm and semen) during his sleep.

• Sperm production begins. Your body is now capable of producing children. Should one of the male's sperm come in contact with a female's egg a pregnancy can occur.