Puberty: Changes for Preteen Girls

Physical Changes for Girls

Your body is changing and so is everything else. But what is causing all these changes? 

Well, you know how everyone says that puberty is all about raging hormones – and it’s kind of true. Hormones that were hibernating suddenly awaken and signal your body to enter puberty. 

You might think that means nothing…hormones, shmormones. But, those hormones cause all the changes that you might associate with puberty.

Since there is so much going on, here’s a timeline so that we can go through the steps chronologically.

Puberty Event

Growth of breasts
Age at which it happens: 8-13

Growth of pubic hair
Age at which it happens: 8-14

Body Growth
Age at which it happens: 9.5-14.5

First Period
Age at which it happens: 10-16.5

Underarm Hair
Age at which it happens: 2 years after pubic hair shows up

Acne
Age at which it happens: Approx. same time as underarm hair

One word of caution: Puberty is not always perfectly regular, so some girls will grow pubic hair before they develop breasts, and that is absolutely normal.

Breasts

Breast development starts between 8 and 13 years of age and continues through puberty. First, the flat area around the nipple (areola) becomes enlarged, and breast tissue forms under the nipple. 

When breast development is complete, each breast is distinct and the areola no longer appears swollen. Breast size varies from woman to woman. You cannot change your breast size without plastic surgery.

 Pubic Hair

Pubic hair starts along the vaginal lips, the outer opening of your private parts. The hair becomes darker and coarser and grows like an inverted triangle. Sometimes, the hair spreads to the insides of your thighs as well. 

 Growing

Puberty also causes you to go through a growth spurt, which results in an average growth of about 3.5 inches a year. The weird thing is that all of you doesn’t grow at the same time. Your head, hands and feet are the first things to grow; followed by your arms and legs; and finally your torso and shoulders.

Height growth is, of course, accompanied by an increase in weight. This weight gain is perfectly normal and a part of puberty. Without gaining this weight, you cannot grow taller, develop breasts or get your first period.

Sweat and Acne

Finally, underarm hair begins to grow. Your sweat and oil-producing glands also start developing, which eventually results in acne when these glands are clogged. 

In order to avoid breakouts, you should wash your face twice daily and, if you regularly break out, it might be useful to consult a dermatologist.

Reviewed by: Adolescent Interest Group

Last reviewed: July 2019