Puberty

Puberty is the time when a child's body changes into an adult body, getting ready for the possibility of having babies. It starts when the brain sends special messages to parts of the body called the ovaries in girls and the testicles in boys. These parts then make new chemicals that cause many changes in the body, like growing taller, growing hair in new places, and developing features that make boys and girls look different.

Girls usually start puberty around age 10½ and finish by ages 15–17. Boys start a little later, around ages 11½–12, and finish by ages 16–17. For girls, a big sign that puberty has started is their first period, which usually happens around age 12½. For boys, a big sign is their first time producing sperm, which usually happens around age 13.

In recent times, children seem to start puberty a bit earlier than they did in the past. This might be because they are healthier and have better food, but it could also be affected by things in the environment. No matter when it starts, puberty is a normal and important part of growing up, helping children become adults.

Differences between male and female puberty

Puberty is when kids start changing into adults. Girls usually start around age 10½, and boys start a bit later, around 11½ to 12. For girls, this process usually finishes by age 15–17, while for boys it can go on until about 16–17.

Boys produce a hormone called testosterone, which helps them grow deeper voices and more muscle. Girls produce hormones like estradiol, which helps their bodies get ready for future families. Boys often grow taller than girls after puberty because their growth happens more slowly over a longer time.

Puberty onset

Puberty is when a child's body changes to become an adult body. Before puberty starts, there is a change called adrenarche. This happens between ages 6 and 10 and can cause hair to appear in certain areas.

The start of puberty is linked to signals from the brain. These signals can cause changes that make puberty start earlier than usual. Scientists think a substance called leptin, which helps control hunger, may play a role. Some genes may also affect when puberty begins.

Effects of early and late puberty onset

Studies have looked at how starting puberty early or late affects boys and girls. For girls, starting puberty early can be hard. They may feel self-conscious and face teasing. This can affect their confidence.

For boys, starting puberty early used to be seen as an advantage. But research shows that early-maturing boys may feel angry or get into trouble. Boys who start puberty later might feel less confident.

Changes in males

See also: Tanner scale

During puberty, boys notice many changes in their bodies. The testicles and scrotum grow bigger, and the penis gets larger too. Boys start making sperm in their testicles. This can lead to their first ejaculation, which often happens around age 13. Sometimes, boys may ejaculate during sleep, called a nocturnal emission.

As puberty goes on, boys may see more hair in places like their underarms, upper lip, and around the beard area. Their voices change and often become deeper because of the growth of the larynx, or voice box. This change usually happens slowly over time.

Changes in females

The first sign that a girl is going through puberty is usually the growth of her breasts. This starts with a small lump under the center of the breast area. Over time, the breasts grow and change shape.

Another change is the growth of hair around the pubic area. This usually starts after the breasts begin to grow. Hair may also grow under the arms later on.

During puberty, a girl’s body also changes shape. Her hips may widen, and she may notice more body fat, especially in areas like the breasts, hips, and thighs. This helps prepare the body for future growth.

Many girls also notice changes in their skin and smell during this time. Some may experience acne, which is a common skin condition during puberty. The body may also start to smell different.

Eventually, most girls will have their first period, called menarche. This usually happens about two years after breast development starts. The average age for this is around 12 or 13, but it can happen earlier or later and still be normal.

The body makes many changes to get ready for adulthood, including growing new hair and changing body shape. These changes are all natural and help the body develop.

Variations

Puberty ends when a person is ready to have children, usually when they reach their full adult height and their bodies are fully developed. For most girls, this happens around age 15, and for most boys, around age 18.

Sometimes, a person might start puberty a little earlier or later than others, and that is normal.

The age when puberty starts can vary a lot. It often begins between ages 10 and 13, but this can change depending on genetics, nutrition, and other factors. The average age can also differ among different groups of people, partly because of diet and health.

Neurohormonal process

The body has a special system that helps start puberty. This system includes the brain, a small gland near the brain, and glands called gonads and adrenal glands. It all begins in the brain.

First, a part of the brain called the hypothalamus starts sending out special signals. These signals tell another gland, the pituitary, to release certain chemicals. These chemicals then tell the ovaries in girls or the testes in boys to start making new hormones. These hormones cause many changes in the body during puberty.

The start of this process can happen a little before we see any changes in the body.

Stages

Puberty happens in several stages. One of the first signs is adrenarche, which usually starts between ages 6 and 8. Next comes gonadarche, around age 10½ for girls and 11½ for boys. In girls, thelarche — the growth of breasts — often begins around age 10½. Pubarche, the growth of pubic hair, typically starts around age 11 for girls and age 12 for boys. For girls, menarche — the first menstrual period — usually happens around age 12½. In boys, spermarche — the first release of sperm — often occurs around age 13.