Growing Up

Our bodies are always changing.

Growing up, some of the biggest changes happen between the ages of 9 and 17. This is when our body develops the ability to produce babies. This is called puberty. During puberty, boys and girls change on the inside and outside. Let’s explore some of the changes girls experience during puberty.

Outside Changes

Getting taller: Sudden growth is one of the first signs of puberty. Girls often grow twice as fast as boys the same age. Our arms, legs and feet usually grow much faster than other parts of the body. In fact, our feet are likely to grow fastest of all, reaching adult sizes long before we reach our adult height. Most of us stop growing completely 1 to 3 years after the start of our menstrual cycle.


Breast development: Between the ages of 8 and 16, our breasts usually start to swell and grow. This is a sign that the breasts are developing milk glands making it possible for us to feed a baby if we choose to get pregnant. Our breasts do not grow all at once. At first, only the nipples and surrounding area begin to stick out. Often, one breast grows faster, but the slower breast will catch up.

Snap shots of Koree growing up

Koree and a friend discussing the many changes in their bodies

Body Hair: During puberty new hair starts to grow in places like under the arms, on the legs, above the lips, on the arms, and on other parts of the body. Hair also begins to grow around the genitals (pubic area). The growth of pubic hair starts very slowly. At first, there are just a few hairs that can barely be seen. The hairs then gradually grow more and end up covering the pubic area in a kind of upside-down triangle. It is not unusual for pubic hair to be a different colour from the hair on the head and it is often coarser than head hair. For many girls, the first period starts 1 to 2 years after pubic hair first starts to appear.


Other Changes: Hips and thighs can start to widen and change our body shape. Our hair and skin can also become oilier. Oily skin can lead to pimples, but these usually become less or go away for most people as they become older (usually around the time they reach the age of 20).

Inside Changes

Puberty is controlled by hormones. Hormones are produced by our brains, reproductive system, and other parts of our body. Hormones stimulate the development of breasts and the menstrual cycle. They also guide other changes of puberty. During puberty, hormones can lead to strong feelings and emotions.

Boys go through their own physical and hormonal changes at around the same time as girls.

Growing up is not a competition. Different people experience changes in their bodies at different times of their lives.

Boy and girl playing football