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Puberty facts for kids

Kids Encyclopedia Facts

Puberty is what happens in children's bodies that changes them into adults. After puberty, people are able to make children.

Puberty is started by hormones, which are chemicals that tell parts of the body to do things. Today, on average, girls start puberty at age 10 or 11, and boys at age 11 or 12. However, people all over the world start puberty at different ages.

How the body controls puberty

Hypophyse
The location of the pituitary gland is shown in orange. The gland makes hormones that cause males' and females' bodies to start puberty.

Puberty is started and carried on by different hormones. Hormones are chemicals that tell parts of the body to do things. Hormones are made by glands in the body. Glands are organs (special parts) of the body that make hormones.

Body changes in males

For most boys, puberty takes about six years and ends when they are about 17 or 18 years old. At the end of puberty, a teenager is usually about 10 to 30 centimetres (cm) (4 to 12 inches (in)) taller, 7 to 29 kilograms (kg) (15 to 65 pounds (lb)) heavier, and stronger. He is also able to make a woman pregnant (have a baby).

Body hair and skin changes

Hair start to grow in the armpits and around the genitalia. The hair on the arms, legs, chest, abdomen and back becomes thicker. Different men have different amounts of body hair. Many boys begin shaving when hair starts growing on their faces.

A larger amount of male hormones in the body cause changes to perspiration (sweat). This gives it a more "adult" body odor or smell. The hormones also cause sebaceous glands in the skin to make more sebum, a type of oil that keeps the skin from getting too dry. Sebum and dead skin cells can mix with a type of germ called bacteria and block pores (tiny openings) in the skin. This causes a skin problem called acne. Most people get acne during puberty. When a person has acne, he gets swellings on his skin called blackheads, whiteheads and pimples. Blackheads and whiteheads are painless, but pimples can be red and painful. They usually form on the face but can also appear on the neck, shoulders, upper back and chest. Oil glands on scalp – the part of the head on which hair grows – also make a lot of sebum. This can cause dandruff, in which small white bits of skin fall from the scalp.

Voice changes

During puberty, a boy's larynx or voicebox also grows larger. This makes the laryngeal prominence or Adam's apple – the lump that sticks out of the front of his neck – larger too. As the larynx grows the vocal folds become longer and thicker, so they vibrate (move back and forth) more slowly. This causes the voice to lower in pitch or tone and become deeper. When this happens, it is sometimes said that the boy's voice has "broken". However, it actually does not happen overnight but over some time. During this time, the voice may sound scratchy. On average, a boy's voice normally reaches its adult sound when he is around 15 years old.

Body growth

Towards the end of puberty, boys go through a "growth spurt" which lasts for about two to three years. During this time, their body grows taller very quickly. When the growth spurt is at its fastest point, some people grow 10 cm (4 in) or more a year. This happens about two years after puberty starts, usually between the ages of 13 and 15. When a boy reaches the end of his growth spurt when he is about 18 years old, he will be at his adult height. His body will not grow much taller after that. Because of their growth spurt, boys' muscles can feel sore. These "growing pains" can feel worse if boys are active and do a lot of exercise. They go away after a while.

Boys grow more slowly than girls, but for a longer time. That is why most men are taller than women. By the end of puberty, adult males have heavier bones and more muscle than females. In an average adult man, muscle makes up 50% and fat 15% of his weight. On the other hand, 40% of an average adult woman's weight is made up of muscle while 27% is made up of fat. Because men have less body fat than women, their hips do not grow bigger. Some bones like those in the jaw and shoulders grow more in males than in females. That is why males have wider faces and shoulders but narrower hips.

Body changes in females

The changes in a girl's body during puberty usually take place between the ages of eight and 18 years. Most girls will have finished puberty around the age of 15. They will have menstruate (have a period) every month, and will be able to get pregnant. They will usually also have reached their full adult height.

Body hair and skin changes

Between the ages of about eight and 14 (on average, at 11 or 12 years), hair start to grow in the armpits and around the genitalia. The hair on the arms and legs also gets thicker, and some girls may have hair appearing on their upper lip and in front of their ears.

Like boys, higher amounts of hormones in the body cause girls' perspiration (sweat) to change. This gives them a more adult body odor or smell. The hormones also cause the skin to produce more sebum (oil), which usually leads to acne.

Menstruation

When girls are between eight and 11 years old, the two ovaries in their body begin to grow bigger. Each ovary is egg-shaped, and is attached to the side wall of the pelvis. The pelvis is a large set of bones in the hips. The ovaries are organs that make female hormones. These hormones cause a girl to grow into a woman, and make her feel like a woman. The hormones also make it possible for females to become pregnant and have babies.

Body growth

Because of more hormones in the body, girls start to have more fat in their breasts, abdomen, hips and thighs. At the age of ten years, the average girl has 6% more body fat than the average boy, but by the end of puberty the difference is nearly 50%. The fat makes sure that a baby growing inside a pregnant woman will have enough nutrients. Also, the bones in the pelvis move further apart to make room for a larger uterus and ovaries, and so there is space for a baby to grow in the uterus and to pass out of the body when it is born. The extra fat and wider hip bones that girls have give them a curvier shape.

Girls also experience a growth spurt during puberty. In the first year after puberty begins, they grow about 8 cm (3 in). They grow even faster the next year or so, then the growth slows down and almost stops when they start menstruating. After a girl's periods begin, she usually does not grow more than 5 cm (2 in) taller.

Emotional changes in males and females

The large amounts of hormones in the bodies of boys and girls during puberty can also affect their emotions. They are often worried about what other people think about them. They can also feel an urge to do things that are dangerous. They sometimes want more independence – more power to decide things for themselves – and can get angry when their parents do not allow them to do things. The brains of teenagers are still growing, and it may take a while before they are mature enough to know how to make good choices about their lives. Therefore, it may be helpful for them to follow the advice of adults they trust, even if it does not make much sense to them at the time.

Culture

Because puberty is the time in a child's life when he or she becomes able to make children, this is seen as very important. Therefore, people in many countries around the world practice Rites of passage to mark this change.

Images for kids

See also

Kids robot.svg In Spanish: Pubertad para niños

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